Description: testing with JUnit4 instead of JUnit5
 The code is designed for testing with JUnit5, but the call useJUnitPlatform()
 in build.gradle is not understood. Thus I patch the files of test classes in
 order to write annotations of JUnit4.
 I am also patching build.gradle for the dependencies.
Author: Pierre Gruet <pgt@debian.org>
Forwarded: not-needed
Last-Update: 2021-05-14

--- a/build.gradle
+++ b/build.gradle
@@ -30,8 +30,9 @@
 
   dependencies {
     compile "org.codehaus.groovy:groovy:$groovyVersion"
-    testImplementation "org.junit.jupiter:junit-jupiter-api:$junitVersion"
-    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
+    //testImplementation "org.junit.jupiter:junit-jupiter-api:$junitVersion"
+    //testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
+    testCompile "junit:junit:4.x"
     testCompile "org.hamcrest:hamcrest-library:$hamcrestVersion"
     testCompile "org.apache.ivy:ivy:$ivyVersion"
     testCompile "commons-io:commons-io:$commonsIoVersion"
@@ -70,7 +71,7 @@
   
   test {
     testLogging.showStandardStreams = true
-    useJUnitPlatform()
+    useJUnit()
   }
   
   artifacts {
--- a/src/test/java/ch/artecat/grengine/GrengineConcurrencyTest.java
+++ b/src/test/java/ch/artecat/grengine/GrengineConcurrencyTest.java
@@ -33,10 +33,13 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 
-class GrengineConcurrencyTest {
+public class GrengineConcurrencyTest {
+
+    public GrengineConcurrencyTest() {
+    }
 
     private final EngineConcurrencyTestFrame frame = new EngineConcurrencyTestFrame();
 
@@ -84,7 +87,7 @@
     }
 
     @Test
-    void testConcurrentNoTopCodeCache() {
+    public void testConcurrentNoTopCodeCache() {
         final LayeredEngine engine = new LayeredEngine.Builder()
                 .setWithTopCodeCache(false)
                 .build();
@@ -93,7 +96,7 @@
     }
 
     @Test
-    void testConcurrentTopCodeCacheParentFirst() {
+    public void testConcurrentTopCodeCacheParentFirst() {
         final LayeredEngine engine = new LayeredEngine.Builder()
                 .setWithTopCodeCache(true)
                 .setTopLoadMode(LoadMode.PARENT_FIRST)
@@ -103,7 +106,7 @@
     }
 
     @Test
-    void testConcurrentTopCodeCacheCurrentFirst() {
+    public void testConcurrentTopCodeCacheCurrentFirst() {
         final LayeredEngine engine = new LayeredEngine.Builder()
                 .setWithTopCodeCache(true)
                 .setTopLoadMode(LoadMode.CURRENT_FIRST)
--- a/src/test/java/ch/artecat/grengine/GrengineGrapeTest.java
+++ b/src/test/java/ch/artecat/grengine/GrengineGrapeTest.java
@@ -33,26 +33,29 @@
 import groovy.grape.Grape;
 import groovy.lang.GroovyClassLoader;
 import org.codehaus.groovy.control.CompilerConfiguration;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.sameInstance;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.Assert.fail;
 
 
-class GrengineGrapeTest {
+public class GrengineGrapeTest {
+
+    public GrengineGrapeTest() {
+    }
 
     @Test
-    void testHelloWorldWithGrape() {
+    public void testHelloWorldWithGrape() {
         Grengine.Grape.newGrengine().run("@Grab('com.google.guava:guava:18.0')\n"
                 + "import com.google.common.base.Ascii\n" +
                 "println \"Grape: 'C' is upper case: ${Ascii.isUpperCase('C' as char)}\"");
     }
 
     @Test
-    void testNoGrapeByDefault() {
+    public void testNoGrapeByDefault() {
         try {
             new Grengine().run("@Grab('com.google.guava:guava:18.0')\n"
                     + "import com.google.common.base.Ascii\n" +
@@ -70,7 +73,7 @@
     }
 
     @Test
-    void testConstructEmpty() {
+    public void testConstructEmpty() {
 
         // when
 
@@ -89,7 +92,7 @@
     }
 
     @Test
-    void testConstructEmpty_parent() {
+    public void testConstructEmpty_parent() {
 
         // given
 
@@ -111,7 +114,7 @@
     }
 
     @Test
-    void testConstructEmpty_config() {
+    public void testConstructEmpty_config() {
 
         // given
 
@@ -133,7 +136,7 @@
     }
 
     @Test
-    void testConstructEmpty_parent_config() {
+    public void testConstructEmpty_parent_config() {
 
         // given
 
@@ -156,7 +159,7 @@
 
 
     @Test
-    void testConstructDir() {
+    public void testConstructDir() {
 
         // when
 
@@ -177,7 +180,7 @@
     }
 
     @Test
-    void testConstructDir_parent() {
+    public void testConstructDir_parent() {
 
         // given
 
@@ -201,7 +204,7 @@
     }
 
     @Test
-    void testConstructDir_config() {
+    public void testConstructDir_config() {
 
         // given
 
@@ -224,7 +227,7 @@
     }
 
     @Test
-    void testConstructDir_parent_config() {
+    public void testConstructDir_parent_config() {
 
         // given
 
@@ -248,7 +251,7 @@
 
 
     @Test
-    void testConstructDirDirMode() {
+    public void testConstructDirDirMode() {
 
         // when
 
@@ -269,7 +272,7 @@
     }
 
     @Test
-    void testConstructDirDirMode_parent() {
+    public void testConstructDirDirMode_parent() {
 
         // given
 
@@ -293,7 +296,7 @@
     }
 
     @Test
-    void testConstructDirDirMode_config() {
+    public void testConstructDirDirMode_config() {
 
         // given
 
@@ -316,7 +319,7 @@
     }
 
     @Test
-    void testConstructDirDirMode_parent_config() {
+    public void testConstructDirDirMode_parent_config() {
 
         // given
 
@@ -340,7 +343,7 @@
 
 
     @Test
-    void testConstructUrl() throws Exception {
+    public void testConstructUrl() throws Exception {
 
         // given
 
@@ -365,7 +368,7 @@
     }
 
     @Test
-    void testConstructUrl_parent() throws Exception {
+    public void testConstructUrl_parent() throws Exception {
 
         // given
 
@@ -390,7 +393,7 @@
     }
 
     @Test
-    void testConstructUrl_config() throws Exception {
+    public void testConstructUrl_config() throws Exception {
 
         // given
 
@@ -414,7 +417,7 @@
     }
 
     @Test
-    void testConstructUrl_parent_config() throws Exception {
+    public void testConstructUrl_parent_config() throws Exception {
 
         // given
 
@@ -458,12 +461,12 @@
 
 
     @Test
-    void testConstructGrape() {
+    public void testConstructGrape() {
         new Grengine.Grape();
     }
 
     @Test
-    void testActivateDeactivate() {
+    public void testActivateDeactivate() {
 
         try {
             assertThat(Grape.getInstance().getClass().getSimpleName(), is("GrapeIvy"));
@@ -507,7 +510,7 @@
     }
 
     @Test
-    void testActivateDifferentLock() {
+    public void testActivateDifferentLock() {
 
         try {
             assertThat(Grape.getInstance().getClass().getSimpleName(), is("GrapeIvy"));
--- a/src/test/java/ch/artecat/grengine/GrengineTest.java
+++ b/src/test/java/ch/artecat/grengine/GrengineTest.java
@@ -60,7 +60,7 @@
 import groovy.lang.GroovyShell;
 import groovy.lang.Script;
 import org.codehaus.groovy.control.CompilerConfiguration;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageContains;
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
@@ -74,22 +74,25 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class GrengineTest {
+public class GrengineTest {
     
+    public GrengineTest() {
+    }
+
     @Test
-    void testHelloWorld() {
+    public void testHelloWorld() {
         new Grengine().run("println 'hello world'");
     }
 
     @Test
-    void testHelloWorldWithClose() {
+    public void testHelloWorldWithClose() {
         final Grengine gren = new Grengine();
         gren.run("print 'hello world '; [1,2,3].each { print it }; println()");
         gren.close();
     }
 
     @Test
-    void testConstructDefaults() {
+    public void testConstructDefaults() {
 
         // given
 
@@ -124,7 +127,7 @@
     }
 
     @Test
-    void testConstructAllDefined() {
+    public void testConstructAllDefined() {
 
         // given
 
@@ -158,7 +161,7 @@
     }
 
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -173,7 +176,7 @@
     }
 
     @Test
-    void testConstructEmpty() {
+    public void testConstructEmpty() {
 
         // when
 
@@ -202,7 +205,7 @@
     }
 
     @Test
-    void testConstructEmpty_WithParent() {
+    public void testConstructEmpty_WithParent() {
 
         // given
 
@@ -235,7 +238,7 @@
     }
 
     @Test
-    void testConstructFromDirWithoutSubDirs() throws Exception {
+    public void testConstructFromDirWithoutSubDirs() throws Exception {
 
         // given
 
@@ -293,7 +296,7 @@
     }
 
     @Test
-    void testConstructFromDirWithoutSubDirs_WithParent() throws Exception {
+    public void testConstructFromDirWithoutSubDirs_WithParent() throws Exception {
 
         // given
 
@@ -352,7 +355,7 @@
 
 
     @Test
-    void testConstructFromDirWithSubDirs() throws Exception {
+    public void testConstructFromDirWithSubDirs() throws Exception {
 
         // given
 
@@ -395,7 +398,7 @@
 
 
     @Test
-    void testConstructFromDirWithoutSubDirsNoTopCodeCache() throws Exception {
+    public void testConstructFromDirWithoutSubDirsNoTopCodeCache() throws Exception {
 
         // given
 
@@ -451,7 +454,7 @@
     }
 
     @Test
-    void testConstructFromCompilerConfig() {
+    public void testConstructFromCompilerConfig() {
 
         // given
 
@@ -475,7 +478,7 @@
     }
 
     @Test
-    void testConstructFromCompilerConfig_WithParent() {
+    public void testConstructFromCompilerConfig_WithParent() {
 
         // given
 
@@ -501,7 +504,7 @@
 
 
     @Test
-    void testConstructFromDirWithoutSubDirs_WithCompilerConfig() throws Exception {
+    public void testConstructFromDirWithoutSubDirs_WithCompilerConfig() throws Exception {
 
         // given
 
@@ -572,7 +575,7 @@
     }
 
     @Test
-    void testConstructFromDirWithoutSubDirs_WithCompilerConfig_WithParent() throws Exception {
+    public void testConstructFromDirWithoutSubDirs_WithCompilerConfig_WithParent() throws Exception {
 
         // given
 
@@ -645,7 +648,7 @@
 
 
     @Test
-    void testConstructFromDirWithSubDirs_WithCompilerConfiguration() throws Exception {
+    public void testConstructFromDirWithSubDirs_WithCompilerConfiguration() throws Exception {
 
         // given
 
@@ -706,7 +709,7 @@
     }
 
     @Test
-    void testConstructFromDirWithSubDirs_WithCompilerConfiguration_WithParent() throws Exception {
+    public void testConstructFromDirWithSubDirs_WithCompilerConfiguration_WithParent() throws Exception {
 
         // given
 
@@ -769,7 +772,7 @@
     }
 
     @Test
-    void testConstructFromDirWithSubDirs_WithParent() throws Exception {
+    public void testConstructFromDirWithSubDirs_WithParent() throws Exception {
 
         // given
 
@@ -818,7 +821,7 @@
 
 
     @Test
-    void testConstructFromUrls() throws Exception {
+    public void testConstructFromUrls() throws Exception {
 
         // given
 
@@ -858,7 +861,7 @@
     }
 
     @Test
-    void testConstructFromUrls_WithParent() throws Exception {
+    public void testConstructFromUrls_WithParent() throws Exception {
 
         // given
 
@@ -901,7 +904,7 @@
 
 
     @Test
-    void testConstructFromUrls_WithCompilerConfiguration() throws Exception {
+    public void testConstructFromUrls_WithCompilerConfiguration() throws Exception {
 
         // given
 
@@ -948,7 +951,7 @@
         assertThat(gren2.run(f2), is(1));
     }
     @Test
-    void testConstructFromUrls_WithCompilerConfiguration_WithParent() throws Exception {
+    public void testConstructFromUrls_WithCompilerConfiguration_WithParent() throws Exception {
 
         // given
 
@@ -998,7 +1001,7 @@
 
 
     @Test
-    void testConstructFromCompilerConfigNull() {
+    public void testConstructFromCompilerConfigNull() {
 
         // when/then
 
@@ -1008,7 +1011,7 @@
     }
 
     @Test
-    void testConstructFromParentParentNull() {
+    public void testConstructFromParentParentNull() {
 
         // when/then
 
@@ -1018,7 +1021,7 @@
     }
 
     @Test
-    void testConstructFromDir_DirNull() {
+    public void testConstructFromDir_DirNull() {
 
         // when/then
 
@@ -1028,7 +1031,7 @@
     }
 
     @Test
-    void testConstructFromDir_ParentNull() {
+    public void testConstructFromDir_ParentNull() {
 
         // when/then
 
@@ -1038,7 +1041,7 @@
     }
 
     @Test
-    void testConstructFromDir_CompilerConfigurationNull() {
+    public void testConstructFromDir_CompilerConfigurationNull() {
 
         // when/then
 
@@ -1048,7 +1051,7 @@
     }
 
     @Test
-    void testConstructFromDirAndCompilerConfiguration_ParentNull() {
+    public void testConstructFromDirAndCompilerConfiguration_ParentNull() {
 
         // when/then
 
@@ -1058,7 +1061,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirMode_DirNull() {
+    public void testConstructFromDirWithDirMode_DirNull() {
 
         // when/then
 
@@ -1068,7 +1071,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirMode_DirModeNull() {
+    public void testConstructFromDirWithDirMode_DirModeNull() {
 
         // when/then
 
@@ -1078,7 +1081,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndCompilerConfiguration_CompilerConfigurationNull() {
+    public void testConstructFromDirWithDirModeAndCompilerConfiguration_CompilerConfigurationNull() {
 
         // when/then
 
@@ -1088,7 +1091,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndCompilerConfiguration_DirNull() {
+    public void testConstructFromDirWithDirModeAndCompilerConfiguration_DirNull() {
 
         // when/then
 
@@ -1098,7 +1101,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndCompilerConfiguration_DirModeNull() {
+    public void testConstructFromDirWithDirModeAndCompilerConfiguration_DirModeNull() {
 
         // when/then
 
@@ -1108,7 +1111,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndParent_ParentNull() {
+    public void testConstructFromDirWithDirModeAndParent_ParentNull() {
 
         // when/then
 
@@ -1118,7 +1121,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndParent_DirNull() {
+    public void testConstructFromDirWithDirModeAndParent_DirNull() {
 
         // when/then
 
@@ -1128,7 +1131,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndParent_DirModeNull() {
+    public void testConstructFromDirWithDirModeAndParent_DirModeNull() {
 
         // when/then
 
@@ -1138,7 +1141,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_ParentNull() {
+    public void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_ParentNull() {
 
         // when/then
 
@@ -1149,7 +1152,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_CompilerConfigurationNull() {
+    public void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_CompilerConfigurationNull() {
 
         // when/then
 
@@ -1160,7 +1163,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_DirNull() {
+    public void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_DirNull() {
 
         // when/then
 
@@ -1171,7 +1174,7 @@
     }
 
     @Test
-    void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_DirModeNull() {
+    public void testConstructFromDirWithDirModeAndParentAndCompilerConfiguration_DirModeNull() {
 
         // when/then
 
@@ -1182,7 +1185,7 @@
     }
 
     @Test
-    void testConstructFromUrls_UrlsNull() {
+    public void testConstructFromUrls_UrlsNull() {
 
         // when/then
 
@@ -1192,7 +1195,7 @@
     }
 
     @Test
-    void testConstructFromUrlsAndCompilerConfiguration_CompilerConfigurationNull() {
+    public void testConstructFromUrlsAndCompilerConfiguration_CompilerConfigurationNull() {
 
         // when/then
 
@@ -1202,7 +1205,7 @@
     }
 
     @Test
-    void testConstructFromUrlsAndCompilerConfiguration_UrlsNull() {
+    public void testConstructFromUrlsAndCompilerConfiguration_UrlsNull() {
 
         // when/then
 
@@ -1212,7 +1215,7 @@
     }
 
     @Test
-    void testConstructFromUrlsAndParent_ParentNull() {
+    public void testConstructFromUrlsAndParent_ParentNull() {
 
         // when/then
 
@@ -1222,7 +1225,7 @@
     }
 
     @Test
-    void testConstructFromUrlsAndParent_UrlsNull() {
+    public void testConstructFromUrlsAndParent_UrlsNull() {
 
         // when/then
 
@@ -1232,7 +1235,7 @@
     }
 
     @Test
-    void testConstructFromUrlsAndParentAndCompilerConfiguration_ParentNull() {
+    public void testConstructFromUrlsAndParentAndCompilerConfiguration_ParentNull() {
 
         // when/then
 
@@ -1242,7 +1245,7 @@
     }
 
     @Test
-    void testConstructFromUrlsAndParentAndCompilerConfiguration_CompilerConfigurationNull() {
+    public void testConstructFromUrlsAndParentAndCompilerConfiguration_CompilerConfigurationNull() {
 
         // when/then
 
@@ -1252,7 +1255,7 @@
     }
 
     @Test
-    void testConstructFromUrlsAndParentAndCompilerConfiguration_UrlsNull() {
+    public void testConstructFromUrlsAndParentAndCompilerConfiguration_UrlsNull() {
 
         // when/then
 
@@ -1263,7 +1266,7 @@
 
 
     @Test
-    void testClose() throws Exception {
+    public void testClose() throws Exception {
 
         // given
 
@@ -1316,7 +1319,7 @@
     }
 
     @Test
-    void testAsClassLoaderBasic() throws Exception {
+    public void testAsClassLoaderBasic() throws Exception {
 
         // given
 
@@ -1358,7 +1361,7 @@
     }
 
     @Test
-    void testAsClassLoaderLoaderNull() {
+    public void testAsClassLoaderLoaderNull() {
 
         // when/then
 
@@ -1368,7 +1371,7 @@
     }
 
     @Test
-    void testAsClassLoaderLoaderForOtherEngine() {
+    public void testAsClassLoaderLoaderForOtherEngine() {
 
         // when/then
 
@@ -1378,7 +1381,7 @@
     }
 
     @Test
-    void testMatrixSource() throws Exception {
+    public void testMatrixSource() throws Exception {
 
         // when
 
@@ -1425,7 +1428,7 @@
     }
 
     @Test
-    void testMatrixLoad() throws Exception {
+    public void testMatrixLoad() throws Exception {
 
         // given
 
@@ -1478,7 +1481,7 @@
     }
 
     @Test
-    void testMatrixCreate() throws Exception {
+    public void testMatrixCreate() throws Exception {
 
         // given
 
@@ -1530,7 +1533,7 @@
     }
 
     @Test
-    void testMatrixBinding() {
+    public void testMatrixBinding() {
 
         // given
 
@@ -1630,7 +1633,7 @@
     }
 
     @Test
-    void testMatrixRun() throws Exception {
+    public void testMatrixRun() throws Exception {
 
         // given
 
@@ -1717,7 +1720,7 @@
 
 
     @Test
-    void testUpdateExceptionsCompileException() throws Exception {
+    public void testUpdateExceptionsCompileException() throws Exception {
 
         // given
 
@@ -1799,7 +1802,7 @@
     }
 
     @Test
-    void testUpdateExceptionsOtherException() {
+    public void testUpdateExceptionsOtherException() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/GrengineVisualPerformanceTest.java
+++ b/src/test/java/ch/artecat/grengine/GrengineVisualPerformanceTest.java
@@ -26,7 +26,7 @@
 
 import groovy.lang.GroovyShell;
 import groovy.lang.Script;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /**
  * Command line visual performance test.
--- a/src/test/java/ch/artecat/grengine/TestUtil.java
+++ b/src/test/java/ch/artecat/grengine/TestUtil.java
@@ -22,13 +22,13 @@
 import java.nio.file.Files;
 
 import org.apache.commons.io.FileUtils;
-import org.junit.jupiter.api.function.Executable;
+import org.junit.function.ThrowingRunnable;
 
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.startsWith;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.Assert.assertThrows;
 
 
 public class TestUtil {
@@ -87,7 +87,7 @@
      * @param expectedMessage expected throwable message text
      */
     public static <T extends Throwable> void assertThrowsMessageIs(
-            final Class<T> expectedType, final Executable executable, final String expectedMessage) {
+            final Class<T> expectedType, final ThrowingRunnable executable, final String expectedMessage) {
         final Throwable t = assertThrows(expectedType, executable);
         assertThat(t.getMessage(), is(expectedMessage));
     }
@@ -101,7 +101,7 @@
      * @param expectedMessagePart text expected to be contained in throwable message
      */
     public static <T extends Throwable> void assertThrowsMessageContains(
-            final Class<T> expectedType, final Executable executable, final String expectedMessagePart) {
+            final Class<T> expectedType, final ThrowingRunnable executable, final String expectedMessagePart) {
         final Throwable t = assertThrows(expectedType, executable);
         assertThat(t.getMessage(), containsString(expectedMessagePart));
     }
@@ -115,7 +115,7 @@
      * @param expectedMessageStart text expected to start the throwable message
      */
     public static <T extends Throwable> void assertThrowsMessageStartsWith(
-            final Class<T> expectedType, final Executable executable, final String expectedMessageStart) {
+            final Class<T> expectedType, final ThrowingRunnable executable, final String expectedMessageStart) {
         final Throwable t = assertThrows(expectedType, executable);
         assertThat(t.getMessage(), startsWith(expectedMessageStart));
     }
@@ -131,14 +131,10 @@
         return new String(new char[n]).replace("\0", s);
     }
 
-    public interface ThrowingRunnable {
-        void run() throws Exception;
-    }
-
     public static void toRuntimeException(ThrowingRunnable run) {
         try {
             run.run();
-        } catch (Exception e) {
+        } catch (Throwable e) {
             throw new RuntimeException(e);
         }
     }
--- a/src/test/java/ch/artecat/grengine/code/BytecodeTest.java
+++ b/src/test/java/ch/artecat/grengine/code/BytecodeTest.java
@@ -16,16 +16,19 @@
 
 package ch.artecat.grengine.code;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-class BytecodeTest {
+public class BytecodeTest {
+
+    public BytecodeTest() {
+    }
 
     @Test
-    void testConstructPlusGetters() {
+    public void testConstructPlusGetters() {
 
         // given
 
@@ -43,7 +46,7 @@
     }
 
     @Test
-    void testToString() {
+    public void testToString() {
 
         // given
 
@@ -62,7 +65,7 @@
     }
     
     @Test
-    void testConstructWithNameNull() {
+    public void testConstructWithNameNull() {
 
         // given
 
@@ -76,7 +79,7 @@
     }
     
     @Test
-    void testConstructWithBytesNull() {
+    public void testConstructWithBytesNull() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/code/ClassNameConflictAnalyzerTest.java
+++ b/src/test/java/ch/artecat/grengine/code/ClassNameConflictAnalyzerTest.java
@@ -30,7 +30,7 @@
 import java.util.Map;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
@@ -40,12 +40,12 @@
 public class ClassNameConflictAnalyzerTest {
 
     @Test
-    void testConstruct() {
+    public void testConstruct() {
         new ClassNameConflictAnalyzer();
     }
     
     @Test
-    void testGetAllClassOrigins() {
+    public void testGetAllClassOrigins() {
 
         // given
 
@@ -98,7 +98,7 @@
     }
     
     @Test
-    void testGetAllClassOriginsCodeLayersNull() {
+    public void testGetAllClassOriginsCodeLayersNull() {
 
         // when/then
 
@@ -109,7 +109,7 @@
     
     
     @Test
-    void testClassOriginsWithDuplicates() {
+    public void testClassOriginsWithDuplicates() {
 
         // given
 
@@ -135,7 +135,7 @@
     }
     
     @Test
-    void testClassOriginsWithDuplicatesCodeLayersNull() {
+    public void testClassOriginsWithDuplicatesCodeLayersNull() {
 
         // when/then
 
@@ -146,7 +146,7 @@
     
     
     @Test
-    void testDetermineClassOriginsWithDuplicateInParent() {
+    public void testDetermineClassOriginsWithDuplicateInParent() {
 
         // given
 
@@ -173,7 +173,7 @@
     }
     
     @Test
-    void testDetermineClassOriginsWithDuplicateInParentParentNull() {
+    public void testDetermineClassOriginsWithDuplicateInParentParentNull() {
 
         // when/then
 
@@ -184,7 +184,7 @@
     }
     
     @Test
-    void testDetermineClassOriginsWithDuplicateInParentCodeLayersNull() {
+    public void testDetermineClassOriginsWithDuplicateInParentCodeLayersNull() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/code/CompiledSourceInfoTest.java
+++ b/src/test/java/ch/artecat/grengine/code/CompiledSourceInfoTest.java
@@ -22,17 +22,20 @@
 import java.util.HashSet;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class CompiledSourceInfoTest {
+public class CompiledSourceInfoTest {
+
+    public CompiledSourceInfoTest() {
+    }
 
     @Test
-    void testConstructPlusGetters() {
+    public void testConstructPlusGetters() {
 
         // given
 
@@ -57,7 +60,7 @@
     }
     
     @Test
-    void testConstructSourceNull() {
+    public void testConstructSourceNull() {
 
         // when/then
 
@@ -68,7 +71,7 @@
     }
     
     @Test
-    void testConstructMainClassNameNull() {
+    public void testConstructMainClassNameNull() {
 
 
         // when/then
@@ -80,7 +83,7 @@
     }
     
     @Test
-    void testConstructClassNamesNull() {
+    public void testConstructClassNamesNull() {
 
 
         // when/then
--- a/src/test/java/ch/artecat/grengine/code/DefaultCodeTest.java
+++ b/src/test/java/ch/artecat/grengine/code/DefaultCodeTest.java
@@ -24,7 +24,7 @@
 import java.util.Map;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
@@ -32,10 +32,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultCodeTest {
+public class DefaultCodeTest {
+
+    public DefaultCodeTest() {
+    }
 
     @Test
-    void testConstructPlusGetters() {
+    public void testConstructPlusGetters() {
 
         // given
 
@@ -115,7 +118,7 @@
     }
     
     @Test
-    void testConstructSourcesNameNull() {
+    public void testConstructSourcesNameNull() {
 
         // when/then
 
@@ -125,7 +128,7 @@
     }
     
     @Test
-    void testConstructCompiledSourceInfoMapNull() {
+    public void testConstructCompiledSourceInfoMapNull() {
 
         // when/then
 
@@ -135,7 +138,7 @@
     }
     
     @Test
-    void testConstructBytecodeMapNull() {
+    public void testConstructBytecodeMapNull() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/code/DefaultSingleSourceCodeTest.java
+++ b/src/test/java/ch/artecat/grengine/code/DefaultSingleSourceCodeTest.java
@@ -24,7 +24,7 @@
 import java.util.Map;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
@@ -32,10 +32,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultSingleSourceCodeTest {
+public class DefaultSingleSourceCodeTest {
+
+    public DefaultSingleSourceCodeTest() {
+    }
 
     @Test
-    void testConstructPlusGetters() {
+    public void testConstructPlusGetters() {
 
         // given
         
@@ -117,7 +120,7 @@
     }
     
     @Test
-    void testConstructSourcesNameNull() {
+    public void testConstructSourcesNameNull() {
 
         // when/then
 
@@ -127,7 +130,7 @@
     }
     
     @Test
-    void testConstructCompiledSourceInfoMapNull() {
+    public void testConstructCompiledSourceInfoMapNull() {
 
         // when/then
 
@@ -137,7 +140,7 @@
     }
     
     @Test
-    void testConstructBytecodeMapNull() {
+    public void testConstructBytecodeMapNull() {
 
         // when/then
 
@@ -147,7 +150,7 @@
     }
     
     @Test
-    void testConstructNotSingleSource() {
+    public void testConstructNotSingleSource() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/code/groovy/DefaultGroovyCompilerFactoryTest.java
+++ b/src/test/java/ch/artecat/grengine/code/groovy/DefaultGroovyCompilerFactoryTest.java
@@ -17,7 +17,7 @@
 package ch.artecat.grengine.code.groovy;
 
 import org.codehaus.groovy.control.CompilerConfiguration;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
@@ -25,10 +25,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultGroovyCompilerFactoryTest {
+public class DefaultGroovyCompilerFactoryTest {
+
+    public DefaultGroovyCompilerFactoryTest() {
+    }
 
     @Test
-    void testConstructDefaults() {
+    public void testConstructDefaults() {
 
         // given
 
@@ -46,7 +49,7 @@
     }
     
     @Test
-    void testConstructAllDefined() {
+    public void testConstructAllDefined() {
 
         // given
 
@@ -67,7 +70,7 @@
     }
     
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -82,7 +85,7 @@
     }
     
     @Test
-    void testConstructorDefaultCompilerConfiguration() {
+    public void testConstructorDefaultCompilerConfiguration() {
 
         // given
 
@@ -100,7 +103,7 @@
     }
     
     @Test
-    void testConstructorSpecificCompilerConfiguration() {
+    public void testConstructorSpecificCompilerConfiguration() {
 
         // given
 
@@ -120,7 +123,7 @@
     }
 
     @Test
-    void testConstructFromConfigNull() {
+    public void testConstructFromConfigNull() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/code/groovy/DefaultGroovyCompilerTest.java
+++ b/src/test/java/ch/artecat/grengine/code/groovy/DefaultGroovyCompilerTest.java
@@ -46,7 +46,7 @@
 import groovy.lang.GroovyClassLoader;
 import org.codehaus.groovy.control.CompilerConfiguration;
 import org.codehaus.groovy.control.customizers.ImportCustomizer;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -59,13 +59,16 @@
 import static org.hamcrest.CoreMatchers.nullValue;
 import static org.hamcrest.CoreMatchers.sameInstance;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.Assert.fail;
 
 
-class DefaultGroovyCompilerTest {
+public class DefaultGroovyCompilerTest {
+
+    public DefaultGroovyCompilerTest() {
+    }
 
     @Test
-    void testConstructDefaults() {
+    public void testConstructDefaults() {
 
         // given
 
@@ -85,7 +88,7 @@
     }
 
     @Test
-    void testConstructAllDefined() {
+    public void testConstructAllDefined() {
 
         // given
 
@@ -109,7 +112,7 @@
     }
 
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -124,7 +127,7 @@
     }
 
     @Test
-    void testConstructorNoArgs() {
+    public void testConstructorNoArgs() {
 
         // when
 
@@ -137,7 +140,7 @@
     }
 
     @Test
-    void testConstructorFromParent() {
+    public void testConstructorFromParent() {
 
         // given
 
@@ -154,7 +157,7 @@
     }
 
     @Test
-    void testConstructorFromParentAndConfig() {
+    public void testConstructorFromParentAndConfig() {
 
         // given
 
@@ -172,7 +175,7 @@
     }
 
     @Test
-    void testConstructFromParentNull() {
+    public void testConstructFromParentNull() {
 
         // when/then
 
@@ -182,7 +185,7 @@
     }
 
     @Test
-    void testConstructFromParentAndConfigParentNull() {
+    public void testConstructFromParentAndConfigParentNull() {
 
         // when/then
 
@@ -192,7 +195,7 @@
     }
 
     @Test
-    void testConstructFromParentAndConfigConfigNull() {
+    public void testConstructFromParentAndConfigConfigNull() {
 
         // when/then
 
@@ -203,7 +206,7 @@
 
 
     @Test
-    void testCompileBasic() throws Exception {
+    public void testCompileBasic() throws Exception {
 
         // given
 
@@ -256,7 +259,7 @@
     }
 
     @Test
-    void testCompileBasicWithTargetDir() throws Exception {
+    public void testCompileBasicWithTargetDir() throws Exception {
 
         // given
 
@@ -323,7 +326,7 @@
     }
 
     @Test
-    void testCompileBasicSingleSource() {
+    public void testCompileBasicSingleSource() {
 
         // given
 
@@ -360,7 +363,7 @@
     }
 
     @Test
-    void testCompileSourcesNull() {
+    public void testCompileSourcesNull() {
 
         // when/then
 
@@ -370,7 +373,7 @@
     }
 
     @Test
-    void testCompileFailsSyntaxWrong() throws Exception {
+    public void testCompileFailsSyntaxWrong() throws Exception {
 
         // given
 
@@ -402,7 +405,7 @@
     }
 
     @Test
-    void testCompileFailsUnknownSource() throws Exception {
+    public void testCompileFailsUnknownSource() throws Exception {
 
         // given
 
@@ -429,7 +432,7 @@
     }
 
     @Test
-    void testCompileFailsSameClassNameTwice() throws Exception {
+    public void testCompileFailsSameClassNameTwice() throws Exception {
 
         // given
 
@@ -460,7 +463,7 @@
     }
 
     @Test
-    void testCompileSameClassNameTwiceDifferentLoaders() throws Exception {
+    public void testCompileSameClassNameTwiceDifferentLoaders() throws Exception {
 
         // given
 
@@ -513,7 +516,7 @@
     }
 
     @Test
-    void testWithGrape() {
+    public void testWithGrape() {
 
         // given
 
@@ -544,7 +547,7 @@
     }
 
     @Test
-    void testWithGrape_configNull() {
+    public void testWithGrape_configNull() {
 
         // given
 
@@ -558,7 +561,7 @@
     }
 
     @Test
-    void testEnableDisableGrapeSupportDefault() {
+    public void testEnableDisableGrapeSupportDefault() {
         try {
 
             // when (enable)
@@ -639,7 +642,7 @@
     }
 
     @Test
-    void testEnableDisableGrapeSupportSpecificLock() {
+    public void testEnableDisableGrapeSupportSpecificLock() {
         try {
 
             // given
@@ -724,7 +727,7 @@
     }
 
     @Test
-    void testEnableGrapeSupport_differentLock() {
+    public void testEnableGrapeSupport_differentLock() {
         try {
 
             // given
@@ -742,7 +745,7 @@
     }
 
     @Test
-    void testEnableGrapeSupport_lockNull() {
+    public void testEnableGrapeSupport_lockNull() {
         try {
 
             // when/then
@@ -756,7 +759,7 @@
     }
 
     @Test
-    void testGetLoaderIfConfigured() {
+    public void testGetLoaderIfConfigured() {
 
         // given
 
@@ -819,7 +822,7 @@
     }
 
     @Test
-    void testGrabs() {
+    public void testGrabs() {
         try {
 
             // given
@@ -960,7 +963,7 @@
     }
 
     @Test
-    void testConcurrentGrabs() {
+    public void testConcurrentGrabs() {
         try {
 
             // given
@@ -1011,7 +1014,7 @@
     }
 
     @Test
-    void testWrappingFails_instanceNotGrapeIvy() {
+    public void testWrappingFails_instanceNotGrapeIvy() {
 
         // given
 
@@ -1043,4 +1046,4 @@
         }
     }
 
-}
\ No newline at end of file
+}
--- a/src/test/java/ch/artecat/grengine/engine/EngineIdTest.java
+++ b/src/test/java/ch/artecat/grengine/engine/EngineIdTest.java
@@ -16,13 +16,16 @@
 
 package ch.artecat.grengine.engine;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 
-class EngineIdTest {
+public class EngineIdTest {
+
+    public EngineIdTest() {
+    }
 
     @Test
-    void testConstruct() {
+    public void testConstruct() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/engine/LayeredEngineConcurrencyTest.java
+++ b/src/test/java/ch/artecat/grengine/engine/LayeredEngineConcurrencyTest.java
@@ -31,10 +31,13 @@
 import java.util.concurrent.ConcurrentHashMap;
 
 import groovy.lang.Script;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 
-class LayeredEngineConcurrencyTest {
+public class LayeredEngineConcurrencyTest {
+
+    public LayeredEngineConcurrencyTest() {
+    }
 
     private final EngineConcurrencyTestFrame frame = new EngineConcurrencyTestFrame();
 
@@ -82,7 +85,7 @@
     }
 
     @Test
-    void testConcurrentNoTopCodeCache() {
+    public void testConcurrentNoTopCodeCache() {
         final LayeredEngine engine = new LayeredEngine.Builder()
                 .setWithTopCodeCache(false)
                 .build();
@@ -91,7 +94,7 @@
     }
 
     @Test
-    void testConcurrentTopCodeCacheParentFirst() {
+    public void testConcurrentTopCodeCacheParentFirst() {
         final LayeredEngine engine = new LayeredEngine.Builder()
                 .setWithTopCodeCache(true)
                 .setTopLoadMode(LoadMode.PARENT_FIRST)
@@ -101,7 +104,7 @@
     }
 
     @Test
-    void testConcurrentTopCodeCacheCurrentFirst() {
+    public void testConcurrentTopCodeCacheCurrentFirst() {
         final LayeredEngine engine = new LayeredEngine.Builder()
                 .setWithTopCodeCache(true)
                 .setTopLoadMode(LoadMode.CURRENT_FIRST)
--- a/src/test/java/ch/artecat/grengine/engine/LayeredEngineTest.java
+++ b/src/test/java/ch/artecat/grengine/engine/LayeredEngineTest.java
@@ -46,7 +46,7 @@
 import java.util.Set;
 
 import groovy.lang.Script;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -56,13 +56,16 @@
 import static org.hamcrest.CoreMatchers.notNullValue;
 import static org.hamcrest.CoreMatchers.sameInstance;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.Assert.fail;
 
 
-class LayeredEngineTest {
+public class LayeredEngineTest {
+
+    public LayeredEngineTest() {
+    }
 
     @Test
-    void testConstructDefaults() {
+    public void testConstructDefaults() {
 
         // given
         
@@ -86,7 +89,7 @@
     }
 
     @Test
-    void testConstructAllDefined() {
+    public void testConstructAllDefined() {
 
         // given
 
@@ -122,7 +125,7 @@
     }
 
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -137,7 +140,7 @@
     }
 
     @Test
-    void testClose() throws Exception {
+    public void testClose() throws Exception {
 
         // given
 
@@ -221,7 +224,7 @@
     }
     
     @Test
-    void testFromCodeLayersNoTopCodeCache() throws Exception {
+    public void testFromCodeLayersNoTopCodeCache() throws Exception {
 
         // given
 
@@ -383,7 +386,7 @@
     }
     
     @Test
-    void testFromCodeLayersNoTopCodeCacheParentFirst() throws Exception {
+    public void testFromCodeLayersNoTopCodeCacheParentFirst() throws Exception {
 
         // given
 
@@ -448,7 +451,7 @@
     }
     
     @Test
-    void testFromCodeLayersNoTopCodeCacheClassNameConflictChecks() throws Exception {
+    public void testFromCodeLayersNoTopCodeCacheClassNameConflictChecks() throws Exception {
         
         // given
 
@@ -503,7 +506,7 @@
 
     
     @Test
-    void testFromSourcesLayersNoTopCodeCache() throws Exception {
+    public void testFromSourcesLayersNoTopCodeCache() throws Exception {
 
         // given
 
@@ -610,7 +613,7 @@
     }
     
     @Test
-    void testFromCodeLayersTopCodeCacheParentFirst() throws Exception {
+    public void testFromCodeLayersTopCodeCacheParentFirst() throws Exception {
 
         // given
 
@@ -719,7 +722,7 @@
     }
 
     @Test
-    void testFromCodeLayersTopCodeCacheCurrentFirst() throws Exception {
+    public void testFromCodeLayersTopCodeCacheCurrentFirst() throws Exception {
 
         // given
 
@@ -844,7 +847,7 @@
     }
 
     @Test
-    void testSetCodeLayersNull() {
+    public void testSetCodeLayersNull() {
 
         // when/then
 
@@ -854,7 +857,7 @@
     }
 
     @Test
-    void testSetCodeLayersBySourceNull() {
+    public void testSetCodeLayersBySourceNull() {
 
         // when/then
 
@@ -864,7 +867,7 @@
     }
 
     @Test
-    void testAsClassLoader() throws Exception {
+    public void testAsClassLoader() throws Exception {
 
         // given
 
@@ -891,7 +894,7 @@
     }
 
     @Test
-    void testAsClassLoaderFindClass() throws Exception {
+    public void testAsClassLoaderFindClass() throws Exception {
 
         // given
 
@@ -920,7 +923,7 @@
     }
 
     @Test
-    void testAsClassLoaderLoaderNull() {
+    public void testAsClassLoaderLoaderNull() {
 
         // when/then
 
@@ -930,7 +933,7 @@
     }
 
     @Test
-    void testAsClassLoaderLoaderForOtherEngine() {
+    public void testAsClassLoaderLoaderForOtherEngine() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/engine/LoaderTest.java
+++ b/src/test/java/ch/artecat/grengine/engine/LoaderTest.java
@@ -33,17 +33,20 @@
 import java.util.HashMap;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class LoaderTest {
+public class LoaderTest {
+
+    public LoaderTest() {
+    }
 
     @Test
-    void testConstructAndGetSetSourceClassLoader() {
+    public void testConstructAndGetSetSourceClassLoader() {
 
         // given
 
@@ -103,7 +106,7 @@
     }
     
     @Test
-    void testConstructEngineIdNull() {
+    public void testConstructEngineIdNull() {
 
         // given
 
@@ -120,7 +123,7 @@
     }
     
     @Test
-    void testConstructSourceClassLoaderNull() {
+    public void testConstructSourceClassLoaderNull() {
 
         // when/then
 
@@ -130,7 +133,7 @@
     }
 
     @Test
-    void testConstructWithClassReleaserAndClose() throws Exception {
+    public void testConstructWithClassReleaserAndClose() throws Exception {
 
         // given
 
@@ -173,7 +176,7 @@
     }
     
     @Test
-    void testEquals() {
+    public void testEquals() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/except/ClassNameConflictExceptionTest.java
+++ b/src/test/java/ch/artecat/grengine/except/ClassNameConflictExceptionTest.java
@@ -23,7 +23,7 @@
 import java.util.List;
 import java.util.Map;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.is;
@@ -31,10 +31,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class ClassNameConflictExceptionTest {
+public class ClassNameConflictExceptionTest {
+
+    public ClassNameConflictExceptionTest() {
+    }
     
     @Test
-    void testConstruct() {
+    public void testConstruct() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/except/CompileExceptionTest.java
+++ b/src/test/java/ch/artecat/grengine/except/CompileExceptionTest.java
@@ -20,7 +20,7 @@
 import ch.artecat.grengine.sources.Sources;
 import ch.artecat.grengine.sources.SourcesUtil;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.is;
@@ -28,10 +28,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class CompileExceptionTest {
+public class CompileExceptionTest {
+
+    public CompileExceptionTest() {
+    }
 
     @Test
-    void testConstructFromMessage() {
+    public void testConstructFromMessage() {
 
         // given
 
@@ -53,7 +56,7 @@
     }
     
     @Test
-    void testConstructFromMessageAndThrowable() {
+    public void testConstructFromMessageAndThrowable() {
 
         // given
 
@@ -76,7 +79,7 @@
     }
 
     @Test
-    void testConstructFromMessageAndThrowableNull() {
+    public void testConstructFromMessageAndThrowableNull() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/except/CreateExceptionTest.java
+++ b/src/test/java/ch/artecat/grengine/except/CreateExceptionTest.java
@@ -16,7 +16,7 @@
 
 package ch.artecat.grengine.except;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.is;
@@ -24,10 +24,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class CreateExceptionTest {
+public class CreateExceptionTest {
+
+    public CreateExceptionTest() {
+    }
 
     @Test
-    void testConstructFromMessage() {
+    public void testConstructFromMessage() {
 
         // given
 
@@ -47,7 +50,7 @@
     }
     
     @Test
-    void testConstructFromMessageAndThrowable() {
+    public void testConstructFromMessageAndThrowable() {
 
         // given
 
@@ -68,7 +71,7 @@
     }
 
     @Test
-    void testConstructFromMessageAndThrowableNull() {
+    public void testConstructFromMessageAndThrowableNull() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/except/GrengineExceptionTest.java
+++ b/src/test/java/ch/artecat/grengine/except/GrengineExceptionTest.java
@@ -16,17 +16,20 @@
 
 package ch.artecat.grengine.except;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.nullValue;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class GrengineExceptionTest {
+public class GrengineExceptionTest {
+
+    public GrengineExceptionTest() {
+    }
 
     @Test
-    void testConstructFromMessage() {
+    public void testConstructFromMessage() {
 
         // given
 
@@ -45,7 +48,7 @@
     }
     
     @Test
-    void testConstructFromMessageAndThrowable() {
+    public void testConstructFromMessageAndThrowable() {
 
         // given
 
@@ -65,7 +68,7 @@
     }
 
     @Test
-    void testConstructFromMessageAndThrowableNull() {
+    public void testConstructFromMessageAndThrowableNull() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/except/LoadExceptionTest.java
+++ b/src/test/java/ch/artecat/grengine/except/LoadExceptionTest.java
@@ -16,7 +16,7 @@
 
 package ch.artecat.grengine.except;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.is;
@@ -24,10 +24,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class LoadExceptionTest {
+public class LoadExceptionTest {
+
+    public LoadExceptionTest() {
+    }
 
     @Test
-    void testConstructFromMessage() {
+    public void testConstructFromMessage() {
 
         // given
 
@@ -47,7 +50,7 @@
     }
     
     @Test
-    void testConstructFromMessageAndThrowable() {
+    public void testConstructFromMessageAndThrowable() {
 
         // given
 
@@ -68,7 +71,7 @@
     }
 
     @Test
-    void testConstructFromMessageAndThrowableNull() {
+    public void testConstructFromMessageAndThrowableNull() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/load/BytecodeClassLoaderConcurrencyTest.java
+++ b/src/test/java/ch/artecat/grengine/load/BytecodeClassLoaderConcurrencyTest.java
@@ -30,15 +30,18 @@
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.toRuntimeException;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class BytecodeClassLoaderConcurrencyTest {
-    
+public class BytecodeClassLoaderConcurrencyTest {
+
+    public BytecodeClassLoaderConcurrencyTest() {
+    }    
+
     private class SlowBytecodeClassLoader extends BytecodeClassLoader {
         private final long delayDefinePackageMs;
         private final long delayDefineClassMs;
@@ -166,19 +169,19 @@
 
 
     @Test
-    void testConcurrentSingleClassNoPackage() {
+    public void testConcurrentSingleClassNoPackage() {
         testGeneric("", "Class1");
     }
     @Test
-    void testConcurrentSingleClassWithPackage() {
+    public void testConcurrentSingleClassWithPackage() {
         testGeneric("a.b.c", "Class1");
     }
     @Test
-    void testConcurrentMultiClassNoPackage() {
+    public void testConcurrentMultiClassNoPackage() {
         testGeneric("", "Class1", "Class2");
     }
     @Test
-    void testConcurrentMultiClassWithPackage() {
+    public void testConcurrentMultiClassWithPackage() {
         testGeneric("a.b.c", "Class1", "Class2");
     }
 
--- a/src/test/java/ch/artecat/grengine/load/BytecodeClassLoaderTest.java
+++ b/src/test/java/ch/artecat/grengine/load/BytecodeClassLoaderTest.java
@@ -36,7 +36,7 @@
 import java.util.Map;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -46,10 +46,13 @@
 import static org.hamcrest.CoreMatchers.sameInstance;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-class BytecodeClassLoaderTest {
+public class BytecodeClassLoaderTest {
     
+    public BytecodeClassLoaderTest() {
+    }
+
     @Test
-    void testConstructAndGetters() {
+    public void testConstructAndGetters() {
 
         // given
 
@@ -69,7 +72,7 @@
     }
     
     @Test
-    void testConstructParentNull() {
+    public void testConstructParentNull() {
 
         // given
 
@@ -84,7 +87,7 @@
     }
     
     @Test
-    void testConstructLoadModeNull() {
+    public void testConstructLoadModeNull() {
 
         // given
 
@@ -100,7 +103,7 @@
     }
     
     @Test
-    void testConstructCodeNull() {
+    public void testConstructCodeNull() {
 
         // given
 
@@ -213,12 +216,12 @@
     }
 
     @Test
-    void testParentRegularClassLoaderParentFirst() throws Exception {
+    public void testParentRegularClassLoaderParentFirst() throws Exception {
         testParentRegularClassLoader(LoadMode.PARENT_FIRST);
     }
 
     @Test
-    void testParentRegularClassLoaderCurrentFirst() throws Exception {
+    public void testParentRegularClassLoaderCurrentFirst() throws Exception {
         testParentRegularClassLoader(LoadMode.CURRENT_FIRST);
     }
 
@@ -326,19 +329,19 @@
     }
 
     @Test
-    void testParentSourceClassLoaderParentFirst() throws Exception {
+    public void testParentSourceClassLoaderParentFirst() throws Exception {
         testParentSourceClassLoader(LoadMode.PARENT_FIRST);
     }
     
     
     @Test
-    void testParentIsSourceClassLoaderCurrentFirst() throws Exception {
+    public void testParentIsSourceClassLoaderCurrentFirst() throws Exception {
         testParentSourceClassLoader(LoadMode.CURRENT_FIRST);
     }
 
 
     @Test
-    void testLoadClassWithResolveCurrentFirst() throws Exception {
+    public void testLoadClassWithResolveCurrentFirst() throws Exception {
 
         // given
 
@@ -361,7 +364,7 @@
     }
 
     @Test
-    void testStaticLoadMainClassBySource() {
+    public void testStaticLoadMainClassBySource() {
 
         // given
 
@@ -402,7 +405,7 @@
     }
     
     @Test
-    void testStaticLoadMainBySourceAndName() {
+    public void testStaticLoadMainBySourceAndName() {
 
         // given
 
@@ -443,7 +446,7 @@
     }
     
     @Test
-    void testClone() {
+    public void testClone() {
 
         // given
 
@@ -473,12 +476,12 @@
     }
 
     @Test
-    void testReleaseClasses() throws Exception {
+    public void testReleaseClasses() throws Exception {
         testReleaseClasses(false);
     }
 
     @Test
-    void testReleaseClassesThrows() throws Exception {
+    public void testReleaseClassesThrows() throws Exception {
         testReleaseClasses(true);
     }
 
@@ -534,7 +537,7 @@
     }
     
     @Test
-    void testThrowsInSynchronizedBlock() {
+    public void testThrowsInSynchronizedBlock() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/load/DefaultClassReleaserTest.java
+++ b/src/test/java/ch/artecat/grengine/load/DefaultClassReleaserTest.java
@@ -20,17 +20,20 @@
 
 import groovy.lang.MetaClass;
 import org.codehaus.groovy.runtime.InvokerHelper;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.not;
 import static org.hamcrest.CoreMatchers.sameInstance;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-class DefaultClassReleaserTest {
+public class DefaultClassReleaserTest {
+
+    public DefaultClassReleaserTest() {
+    }
     
     @Test
-    void testGetInstance() {
+    public void testGetInstance() {
 
         // when
         final ClassReleaser releaser1 = DefaultClassReleaser.getInstance();
@@ -43,7 +46,7 @@
     }
 
     @Test
-    void testReleaseBasic() {
+    public void testReleaseBasic() {
 
         // hard to test in full detail because depends also on Groovy version,
         // so only this basic test here, testing elsewhere that allows to GC
--- a/src/test/java/ch/artecat/grengine/load/DefaultTopCodeCacheFactoryTest.java
+++ b/src/test/java/ch/artecat/grengine/load/DefaultTopCodeCacheFactoryTest.java
@@ -19,7 +19,7 @@
 import ch.artecat.grengine.code.CompilerFactory;
 import ch.artecat.grengine.code.groovy.DefaultGroovyCompilerFactory;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -28,10 +28,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultTopCodeCacheFactoryTest {
+public class DefaultTopCodeCacheFactoryTest {
+
+    public DefaultTopCodeCacheFactoryTest() {
+    }
 
     @Test
-    void testConstructFromBuilderAndGetters() {
+    public void testConstructFromBuilderAndGetters() {
 
         // given
 
@@ -61,7 +64,7 @@
     }
 
     @Test
-    void testConstructDefault() {
+    public void testConstructDefault() {
 
         // when
 
@@ -74,7 +77,7 @@
     }
     
     @Test
-    void testConstructFromCompilerFactory() {
+    public void testConstructFromCompilerFactory() {
 
         // given
 
@@ -90,7 +93,7 @@
     }
     
     @Test
-    void testConstructFromCompilerFactoryNull() {
+    public void testConstructFromCompilerFactoryNull() {
 
         // when/then
 
@@ -100,7 +103,7 @@
     }
     
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/load/DefaultTopCodeCacheTest.java
+++ b/src/test/java/ch/artecat/grengine/load/DefaultTopCodeCacheTest.java
@@ -19,7 +19,7 @@
 import ch.artecat.grengine.code.CompilerFactory;
 import ch.artecat.grengine.code.groovy.DefaultGroovyCompilerFactory;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -29,10 +29,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultTopCodeCacheTest {
+public class DefaultTopCodeCacheTest {
+
+    public DefaultTopCodeCacheTest() {
+    }
 
     @Test
-    void testConstructAndGettersAndMore() {
+    public void testConstructAndGettersAndMore() {
 
         // given
         
@@ -90,7 +93,7 @@
     }
     
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -105,7 +108,7 @@
     }
 
     @Test
-    void testSetParentNull() {
+    public void testSetParentNull() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/load/LayeredClassLoaderMatrixTest.java
+++ b/src/test/java/ch/artecat/grengine/load/LayeredClassLoaderMatrixTest.java
@@ -34,7 +34,7 @@
 import java.util.List;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageStartsWith;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -55,7 +55,10 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class LayeredClassLoaderMatrixTest {
+public class LayeredClassLoaderMatrixTest {
+
+    public LayeredClassLoaderMatrixTest() {
+    }
 
     // whether the parent class loader of the layered class loader to test
     // is a source class loader or not
@@ -457,66 +460,66 @@
 
     // top off, top sources changed
     @Test
-    void testParentRegularClassLoader_LayersParentFirst_TopOff_SourcesChanged() throws Exception {
+    public void testParentRegularClassLoader_LayersParentFirst_TopOff_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_CHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersParentFirst_TopOff_SourcesChanged() throws Exception {
+    public void testParentSourceClassLoader_LayersParentFirst_TopOff_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_CHANGED);
     }
     @Test
-    void testParentRegularClassLoader_LayersCurrentFirst_TopOff_SourcesChanged() throws Exception {
+    public void testParentRegularClassLoader_LayersCurrentFirst_TopOff_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_CHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersCurrentFirst_TopOff_SourcesChanged() throws Exception {
+    public void testParentSourceClassLoader_LayersCurrentFirst_TopOff_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_CHANGED);
     }
 
     // top parent first, top sources changed
     @Test
-    void testParentRegularClassLoader_LayersParentFirst_TopParentFirst_SourcesChanged() throws Exception {
+    public void testParentRegularClassLoader_LayersParentFirst_TopParentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_CHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersParentFirst_TopParentFirst_SourcesChanged() throws Exception {
+    public void testParentSourceClassLoader_LayersParentFirst_TopParentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_CHANGED);
     }
     @Test
-    void testParentRegularClassLoader_LayersCurrentFirst_TopParentFirst_SourcesChanged() throws Exception {
+    public void testParentRegularClassLoader_LayersCurrentFirst_TopParentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_CHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersCurrentFirst_TopParentFirst_SourcesChanged() throws Exception {
+    public void testParentSourceClassLoader_LayersCurrentFirst_TopParentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_CHANGED);
     }
 
     // top current first, top sources changed
     @Test
-    void testParentRegularClassLoader_LayersParentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
+    public void testParentRegularClassLoader_LayersParentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_CHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersParentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
+    public void testParentSourceClassLoader_LayersParentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_CHANGED);
     }
     @Test
-    void testParentRegularClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
+    public void testParentRegularClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_CHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
+    public void testParentSourceClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_CHANGED);
     }
@@ -524,73 +527,73 @@
 
     // top off, top sources unchanged
     @Test
-    void testParentRegularClassLoader_LayersParentFirst_TopOff_SourcesUnchanged() throws Exception {
+    public void testParentRegularClassLoader_LayersParentFirst_TopOff_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersParentFirst_TopOff_SourcesUnchanged() throws Exception {
+    public void testParentSourceClassLoader_LayersParentFirst_TopOff_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentRegularClassLoader_LayersCurrentFirst_TopOff_SourcesUnchanged() throws Exception {
+    public void testParentRegularClassLoader_LayersCurrentFirst_TopOff_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersCurrentFirst_TopOff_SourcesUnchanged() throws Exception {
+    public void testParentSourceClassLoader_LayersCurrentFirst_TopOff_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_OFF, SOURCES_UNCHANGED);
     }
 
     // top parent first, top sources unchanged
     @Test
-    void testParentRegularClassLoader_LayersParentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
+    public void testParentRegularClassLoader_LayersParentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersParentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
+    public void testParentSourceClassLoader_LayersParentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentRegularClassLoader_LayersCurrentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
+    public void testParentRegularClassLoader_LayersCurrentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersCurrentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
+    public void testParentSourceClassLoader_LayersCurrentFirst_TopParentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_PARENT_FIRST, SOURCES_UNCHANGED);
     }
 
     // top current first, top sources unchanged
     @Test
-    void testParentRegularClassLoader_LayersParentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
+    public void testParentRegularClassLoader_LayersParentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersParentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
+    public void testParentSourceClassLoader_LayersParentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_PARENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentRegularClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
+    public void testParentRegularClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_REGULAR_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_UNCHANGED);
     }
     @Test
-    void testParentSourceClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
+    public void testParentSourceClassLoader_LayersCurrentFirst_TopCurrentFirst_SourcesUnchanged() throws Exception {
         testGeneric(PARENT_IS_SOURCE_CLASS_LOADER, CODE_LAYERS_CURRENT_FIRST,
                 TOP_CODE_CACHE_CURRENT_FIRST, SOURCES_UNCHANGED);
     }
 
 
     @Test
-    void testExtraNoCodeLayers_ParentRegularClassLoader_LayersParentFirst_TopOff_SourcesChanged() throws Exception {
+    public void testExtraNoCodeLayers_ParentRegularClassLoader_LayersParentFirst_TopOff_SourcesChanged() throws Exception {
 
         // given
 
@@ -617,7 +620,7 @@
     }
 
     @Test
-    void testExtraSourcesChangedTop_ParentSourceClassLoader_LayersParentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
+    public void testExtraSourcesChangedTop_ParentSourceClassLoader_LayersParentFirst_TopCurrentFirst_SourcesChanged() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/load/LayeredClassLoaderTest.java
+++ b/src/test/java/ch/artecat/grengine/load/LayeredClassLoaderTest.java
@@ -30,7 +30,7 @@
 import java.util.List;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -42,10 +42,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class LayeredClassLoaderTest {
+public class LayeredClassLoaderTest {
     
+    public LayeredClassLoaderTest() {
+    }
+
     @Test
-    void testConstructFromCodeLayersDefaults() {
+    public void testConstructFromCodeLayersDefaults() {
 
         // given
         
@@ -85,7 +88,7 @@
     }
 
     @Test
-    void testConstructFromCodeLayersAllSet() {
+    public void testConstructFromCodeLayersAllSet() {
 
         // given
 
@@ -122,7 +125,7 @@
     }
 
     @Test
-    void testConstructFromSourcesLayersDefaults() {
+    public void testConstructFromSourcesLayersDefaults() {
 
         // given
 
@@ -150,7 +153,7 @@
     }
 
     @Test
-    void testConstructFromSourcesLayersAllSet() {
+    public void testConstructFromSourcesLayersAllSet() {
 
         // given
 
@@ -187,7 +190,7 @@
     }
     
     @Test
-    void testSetLayersWithVarargs() {
+    public void testSetLayersWithVarargs() {
 
         // given
 
@@ -233,7 +236,7 @@
     }
     
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -249,7 +252,7 @@
     
     
     @Test
-    void testClone_NoTopCodeCache() {
+    public void testClone_NoTopCodeCache() {
 
         // given
 
@@ -269,7 +272,7 @@
     }
     
     @Test
-    void testClone_WithTopCodeCache() {
+    public void testClone_WithTopCodeCache() {
 
         // given
 
@@ -293,7 +296,7 @@
     }
     
     @Test
-    void testCloneWithSeparateTopCodeCache_NoTopCodeCache() {
+    public void testCloneWithSeparateTopCodeCache_NoTopCodeCache() {
 
         // given
 
@@ -313,7 +316,7 @@
     }
     
     @Test
-    void testCloneWithSeparateTopCodeCache_WithTopCodeCache() {
+    public void testCloneWithSeparateTopCodeCache_WithTopCodeCache() {
 
         // given
 
@@ -339,7 +342,7 @@
     }
 
     @Test
-    void testReleaseClasses() throws Exception {
+    public void testReleaseClasses() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/load/LoadModeTest.java
+++ b/src/test/java/ch/artecat/grengine/load/LoadModeTest.java
@@ -16,15 +16,18 @@
 
 package ch.artecat.grengine.load;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-class LoadModeTest {
+public class LoadModeTest {
+
+    public LoadModeTest() {
+    }
 
     @Test
-    void testValueOf() {
+    public void testValueOf() {
 
         // when/then
 
@@ -33,7 +36,7 @@
     }
     
     @Test
-    void testValues() {
+    public void testValues() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/source/DefaultFileSourceTest.java
+++ b/src/test/java/ch/artecat/grengine/source/DefaultFileSourceTest.java
@@ -21,7 +21,7 @@
 import java.io.File;
 import java.io.IOException;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -29,10 +29,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultFileSourceTest {
+public class DefaultFileSourceTest {
+
+    public DefaultFileSourceTest() {
+    }
 
     @Test
-    void testConstructFromFilePlusGetters() throws IOException {
+    public void testConstructFromFilePlusGetters() throws IOException {
 
         // given
 
@@ -54,7 +57,7 @@
     }
     
     @Test
-    void testConstructFromFileWithFileNull() {
+    public void testConstructFromFileWithFileNull() {
 
         // when/then
 
@@ -64,7 +67,7 @@
     }
 
     @Test
-    void testConstructorFromFileExceptionGetCanonicalFile() {
+    public void testConstructorFromFileExceptionGetCanonicalFile() {
 
         // given
 
@@ -81,7 +84,7 @@
     }
 
     @Test
-    void testEquals() throws Exception {
+    public void testEquals() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/source/DefaultSourceFactoryTest.java
+++ b/src/test/java/ch/artecat/grengine/source/DefaultSourceFactoryTest.java
@@ -24,7 +24,7 @@
 import java.io.File;
 import java.net.URL;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -35,10 +35,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultSourceFactoryTest {
+public class DefaultSourceFactoryTest {
+
+    public DefaultSourceFactoryTest() {
+    }
 
     @Test
-    void testFromTextNoNameNoIdTracking() {
+    public void testFromTextNoNameNoIdTracking() {
 
         // given
 
@@ -67,7 +70,7 @@
     }
 
     @Test
-    void testFromTextNoNameWithIdTracking() {
+    public void testFromTextNoNameWithIdTracking() {
 
         // given
 
@@ -99,7 +102,7 @@
     }
 
     @Test
-    void testFromTextWithNameNoIdTracking() {
+    public void testFromTextWithNameNoIdTracking() {
 
         // given
 
@@ -130,7 +133,7 @@
     }
 
     @Test
-    void testFromTextWithNameWithIdTracking() {
+    public void testFromTextWithNameWithIdTracking() {
 
         // given
 
@@ -164,7 +167,7 @@
     }
     
     @Test
-    void testFromFileNoLastModifiedTracking() throws Exception {
+    public void testFromFileNoLastModifiedTracking() throws Exception {
 
         // given
 
@@ -188,7 +191,7 @@
     }
         
     @Test
-    void testFromFileWithLastModifiedTracking() throws Exception {
+    public void testFromFileWithLastModifiedTracking() throws Exception {
 
         // given
 
@@ -220,7 +223,7 @@
     }
         
     @Test
-    void testFromUrlNoTracking() throws Exception {
+    public void testFromUrlNoTracking() throws Exception {
 
         // given
 
@@ -243,7 +246,7 @@
     }
     
     @Test
-    void testFromUrlWithTrackingNoLatency() throws Exception {
+    public void testFromUrlWithTrackingNoLatency() throws Exception {
 
         // given
 
@@ -334,7 +337,7 @@
     }
     
     @Test
-    void testFromUrlWithTrackingWithLatency() throws Exception {
+    public void testFromUrlWithTrackingWithLatency() throws Exception {
 
         // given
 
@@ -383,7 +386,7 @@
     }
     
     @Test
-    void testConstructWithTextSourceIdTrackingFromTextWithTextNull() {
+    public void testConstructWithTextSourceIdTrackingFromTextWithTextNull() {
 
         // given
 
@@ -399,7 +402,7 @@
     }
     
     @Test
-    void testConstructWithTextSourceIdTrackingFromTextAndNameWithTextNull() {
+    public void testConstructWithTextSourceIdTrackingFromTextAndNameWithTextNull() {
 
         // given
 
@@ -415,7 +418,7 @@
     }
 
     @Test
-    void testConstructWithTextSourceIdTrackingFromTextAndNameWithNameNull() {
+    public void testConstructWithTextSourceIdTrackingFromTextAndNameWithNameNull() {
 
         // given
 
@@ -432,7 +435,7 @@
 
 
     @Test
-    void testModifyBuilderAfterUseAndGetBuilder() {
+    public void testModifyBuilderAfterUseAndGetBuilder() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/source/DefaultTextSourceTest.java
+++ b/src/test/java/ch/artecat/grengine/source/DefaultTextSourceTest.java
@@ -18,17 +18,20 @@
 
 import ch.artecat.grengine.TestUtil;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultTextSourceTest {
+public class DefaultTextSourceTest {
+
+    public DefaultTextSourceTest() {
+    }
 
     @Test
-    void testConstructFromTextPlusGetters() {
+    public void testConstructFromTextPlusGetters() {
 
         // given
 
@@ -48,7 +51,7 @@
     }
 
     @Test
-    void testConstructFromTextAndNamePlusGetters() {
+    public void testConstructFromTextAndNamePlusGetters() {
 
         // given
 
@@ -69,7 +72,7 @@
     }
 
     @Test
-    void testConstructFromTextWithTextNull() {
+    public void testConstructFromTextWithTextNull() {
 
         // when/then
 
@@ -79,7 +82,7 @@
     }
 
     @Test
-    void testConstructFromTextAndNameWithTextNull() {
+    public void testConstructFromTextAndNameWithTextNull() {
 
         // when/then
 
@@ -89,7 +92,7 @@
     }
 
     @Test
-    void testConstructFromTextAndNameWithNameNull() {
+    public void testConstructFromTextAndNameWithNameNull() {
 
         // when/then
 
@@ -99,7 +102,7 @@
     }
 
     @Test
-    void testLongText() {
+    public void testLongText() {
 
         // given
 
@@ -119,7 +122,7 @@
     }
 
     @Test
-    void testTextWithLineBreaks() {
+    public void testTextWithLineBreaks() {
 
         // given
 
@@ -139,7 +142,7 @@
     }
 
     @Test
-    void testEquals() {
+    public void testEquals() {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/source/DefaultUrlSourceTest.java
+++ b/src/test/java/ch/artecat/grengine/source/DefaultUrlSourceTest.java
@@ -21,7 +21,7 @@
 import java.io.File;
 import java.net.URL;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -29,10 +29,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DefaultUrlSourceTest {
+public class DefaultUrlSourceTest {
+
+    public DefaultUrlSourceTest() {
+    }
 
     @Test
-    void testConstructFromUrlPlusGetters() throws Exception {
+    public void testConstructFromUrlPlusGetters() throws Exception {
 
         // given
 
@@ -55,7 +58,7 @@
     }
     
     @Test
-    void testConstructFromUrlWithUrlNull() {
+    public void testConstructFromUrlWithUrlNull() {
 
         // when/then
 
@@ -65,7 +68,7 @@
     }
         
     @Test
-    void testEquals() throws Exception {
+    public void testEquals() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/source/MockFileSourceTest.java
+++ b/src/test/java/ch/artecat/grengine/source/MockFileSourceTest.java
@@ -20,7 +20,7 @@
 
 import java.io.File;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.createTestDir;
 import static org.hamcrest.CoreMatchers.is;
@@ -28,10 +28,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class MockFileSourceTest {
+public class MockFileSourceTest {
+
+    public MockFileSourceTest() {
+    }
 
     @Test
-    void testMockFileSource() throws Exception {
+    public void testMockFileSource() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/source/MockFileTest.java
+++ b/src/test/java/ch/artecat/grengine/source/MockFileTest.java
@@ -20,7 +20,7 @@
 
 import java.io.File;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.createTestDir;
 import static org.hamcrest.CoreMatchers.is;
@@ -28,10 +28,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class MockFileTest {
+public class MockFileTest {
     
+    public MockFileTest() {
+    }
+
     @Test
-    void testMockFile() throws Exception {
+    public void testMockFile() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/source/SourceSetStateTest.java
+++ b/src/test/java/ch/artecat/grengine/source/SourceSetStateTest.java
@@ -19,16 +19,19 @@
 import java.util.HashSet;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-class SourceSetStateTest {
+public class SourceSetStateTest {
+
+    public SourceSetStateTest() {
+    }
 
     @Test
-    void testConstructAndUpdate() throws Exception {
+    public void testConstructAndUpdate() throws Exception {
 
         // given
         
@@ -114,7 +117,7 @@
     }
     
     @Test
-    void testConstructWithSourceSetNull() {
+    public void testConstructWithSourceSetNull() {
 
         // when/then
 
@@ -124,7 +127,7 @@
     }
     
     @Test
-    void testUpdateWithSourceSetNull() {
+    public void testUpdateWithSourceSetNull() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/source/SourceUtilTest.java
+++ b/src/test/java/ch/artecat/grengine/source/SourceUtilTest.java
@@ -27,7 +27,7 @@
 import java.util.Map;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageStartsWith;
@@ -37,15 +37,18 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class SourceUtilTest {
+public class SourceUtilTest {
+
+    public SourceUtilTest() {
+    }
 
     @Test
-    void testConstructor() {
+    public void testConstructor() {
         new SourceUtil();
     }
     
     @Test
-    void testTextsToSourceSetNoNamesWithFactoryWithCollection() {
+    public void testTextsToSourceSetNoNamesWithFactoryWithCollection() {
 
         // given
 
@@ -65,7 +68,7 @@
     }
     
     @Test
-    void testTextsToSourceSetNoNamesWithFactoryWithArrayVarargs() {
+    public void testTextsToSourceSetNoNamesWithFactoryWithArrayVarargs() {
 
         // given
 
@@ -84,7 +87,7 @@
     }
 
     @Test
-    void testTextsToSourceSetNoNamesNoFactoryWithCollection() {
+    public void testTextsToSourceSetNoNamesNoFactoryWithCollection() {
 
         // given
 
@@ -104,7 +107,7 @@
     }
     
     @Test
-    void testTextsToSourceSetNoNamesNoFactoryWithArrayVarargs() {
+    public void testTextsToSourceSetNoNamesNoFactoryWithArrayVarargs() {
 
         // given
 
@@ -123,7 +126,7 @@
     }
     
     @Test
-    void testTextsToSourceSetWithNamesWithFactory() {
+    public void testTextsToSourceSetWithNamesWithFactory() {
 
         // given
 
@@ -147,7 +150,7 @@
     }
 
     @Test
-    void testTextsToSourceSetWithNamesNoFactory() {
+    public void testTextsToSourceSetWithNamesNoFactory() {
 
         // given
 
@@ -172,7 +175,7 @@
     
     
     @Test
-    void testFilesToSourceSetWithFactoryWithCollection() {
+    public void testFilesToSourceSetWithFactoryWithCollection() {
 
         // given
 
@@ -192,7 +195,7 @@
     }
 
     @Test
-    void testFilesToSourceSetWithFactoryWithArrayVarargs() {
+    public void testFilesToSourceSetWithFactoryWithArrayVarargs() {
 
         // given
 
@@ -211,7 +214,7 @@
     }
 
     @Test
-    void testFilesToSourceSetNoFactoryWithCollection() {
+    public void testFilesToSourceSetNoFactoryWithCollection() {
 
         // given
 
@@ -231,7 +234,7 @@
     }
 
     @Test
-    void testFilesToSourceSetNoFactoryWithArrayVarargs() {
+    public void testFilesToSourceSetNoFactoryWithArrayVarargs() {
 
         // given
 
@@ -251,7 +254,7 @@
 
     
     @Test
-    void testUrlsToSourceSetWithFactoryWithCollection() throws Exception {
+    public void testUrlsToSourceSetWithFactoryWithCollection() throws Exception {
 
         // given
 
@@ -271,7 +274,7 @@
     }
 
     @Test
-    void testUrlsToSourceSetWithFactoryWithArrayVarargs() throws Exception {
+    public void testUrlsToSourceSetWithFactoryWithArrayVarargs() throws Exception {
 
         // given
 
@@ -290,7 +293,7 @@
     }
 
     @Test
-    void testUrlsToSourceSetNoFactoryWithCollection() throws Exception {
+    public void testUrlsToSourceSetNoFactoryWithCollection() throws Exception {
 
         // given
 
@@ -310,7 +313,7 @@
     }
 
     @Test
-    void testUrlsToSourceSetNoFactoryWithArrayVarargs() throws Exception {
+    public void testUrlsToSourceSetNoFactoryWithArrayVarargs() throws Exception {
 
         // given
 
@@ -330,7 +333,7 @@
 
     
     @Test
-    void testSourceToSourceSet() {
+    public void testSourceToSourceSet() {
 
         // given
 
@@ -347,7 +350,7 @@
     }
     
     @Test
-    void testSourceCollectionToSourceSet() {
+    public void testSourceCollectionToSourceSet() {
 
         // given
 
@@ -367,7 +370,7 @@
     }
     
     @Test
-    void testSourceArrayVarargsToSourceSet() {
+    public void testSourceArrayVarargsToSourceSet() {
 
         // given
 
@@ -387,7 +390,7 @@
     
 
     @Test
-    void testMd5() {
+    public void testMd5() {
 
         // when/then (RFC 1321 test vectors)
 
@@ -401,7 +404,7 @@
     }
     
     @Test
-    void testHash() {
+    public void testHash() {
 
         // when/then
 
@@ -409,7 +412,7 @@
     }
     
     @Test
-    void testHashUnsupportedDigestAlgorithm() {
+    public void testHashUnsupportedDigestAlgorithm() {
 
         // when/then
 
@@ -419,7 +422,7 @@
     }
     
     @Test
-    void testGetTextStartNoLineBreaksNullText() {
+    public void testGetTextStartNoLineBreaksNullText() {
 
         // when/then
 
@@ -427,7 +430,7 @@
     }
     
     @Test
-    void testGetTextStartNoLineBreaksNegMaxLen() {
+    public void testGetTextStartNoLineBreaksNegMaxLen() {
 
         // when/then
 
@@ -437,7 +440,7 @@
     }
     
     @Test
-    void testGetTextStartNoLineBreaksMaxLenLessThan10() {
+    public void testGetTextStartNoLineBreaksMaxLenLessThan10() {
 
         // when/then
 
@@ -447,7 +450,7 @@
     }
 
     @Test
-    void testGetTextStartNoLineBreaks() {
+    public void testGetTextStartNoLineBreaks() {
         assertThat(SourceUtil.getTextStartNoLineBreaks("hello", 10), is("hello"));
         assertThat(SourceUtil.getTextStartNoLineBreaks("hello1", 10), is("hello1"));
         assertThat(SourceUtil.getTextStartNoLineBreaks("hello12", 10), is("hello12"));
@@ -468,7 +471,7 @@
     }
 
     @Test
-    void testReadUrlText() throws Exception {
+    public void testReadUrlText() throws Exception {
 
         // given
 
@@ -488,7 +491,7 @@
     }
     
     @Test
-    void testReadUrlTextEmptyText() throws Exception {
+    public void testReadUrlTextEmptyText() throws Exception {
 
         // given
 
@@ -508,7 +511,7 @@
     }
     
     @Test
-    void testReadUrlTextNothingThere() throws Exception {
+    public void testReadUrlTextNothingThere() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/sources/CompositeSourcesTest.java
+++ b/src/test/java/ch/artecat/grengine/sources/CompositeSourcesTest.java
@@ -28,7 +28,7 @@
 import java.util.LinkedList;
 import java.util.List;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -38,10 +38,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class CompositeSourcesTest {
+public class CompositeSourcesTest {
+
+    public CompositeSourcesTest() {
+    }
 
     @Test
-    void testConstructDefaults() throws Exception {
+    public void testConstructDefaults() throws Exception {
 
         // given
 
@@ -78,7 +81,7 @@
     }
     
     @Test
-    void testConstructAllDefined() throws Exception {
+    public void testConstructAllDefined() throws Exception {
 
         // given
 
@@ -120,7 +123,7 @@
     }
     
     @Test
-    void testConstructSourcesCollectionNull() {
+    public void testConstructSourcesCollectionNull() {
 
         // when/then
 
@@ -130,7 +133,7 @@
     }
 
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -146,7 +149,7 @@
     }
     
     @Test
-    void testLastModified() throws Exception {
+    public void testLastModified() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/sources/DirBasedSourcesTest.java
+++ b/src/test/java/ch/artecat/grengine/sources/DirBasedSourcesTest.java
@@ -33,7 +33,7 @@
 import java.util.Map;
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static ch.artecat.grengine.TestUtil.createTestDir;
@@ -43,12 +43,15 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DirBasedSourcesTest {
+public class DirBasedSourcesTest {
     
+    public DirBasedSourcesTest() {
+    }
+
     private final boolean isWindows = System.getProperty("os.name").startsWith("Windows");
 
     @Test
-    void testConstructDefaults() throws Exception {
+    public void testConstructDefaults() throws Exception {
 
         // given
 
@@ -85,7 +88,7 @@
     }
     
     @Test
-    void testConstructAllDefined() throws Exception {
+    public void testConstructAllDefined() throws Exception {
 
         // given
 
@@ -131,7 +134,7 @@
     }
     
     @Test
-    void testConstructDirNull() {
+    public void testConstructDirNull() {
 
         // when/then
 
@@ -141,7 +144,7 @@
     }
     
     @Test
-    void testModifyBuilderAfterUse() throws Exception {
+    public void testModifyBuilderAfterUse() throws Exception {
 
         // given
 
@@ -157,7 +160,7 @@
     }
     
     @Test
-    void testGetSourcesNoSubDirsDefaultExtensions() throws Exception {
+    public void testGetSourcesNoSubDirsDefaultExtensions() throws Exception {
 
         // given
 
@@ -186,7 +189,7 @@
     }
     
     @Test
-    void testGetSourcesWithSubDirsDefaultExtensions() throws Exception {
+    public void testGetSourcesWithSubDirsDefaultExtensions() throws Exception {
 
         // given
 
@@ -215,7 +218,7 @@
     }
     
     @Test
-    void testGetSourcesNoSubDirsSpecificExtensions() throws Exception {
+    public void testGetSourcesNoSubDirsSpecificExtensions() throws Exception {
 
         // given
 
@@ -244,7 +247,7 @@
     }
 
     @Test
-    void testGetSourcesWithSubDirsSpecificExtensions() throws Exception {
+    public void testGetSourcesWithSubDirsSpecificExtensions() throws Exception {
 
         // given
 
@@ -276,7 +279,7 @@
     }
 
     @Test
-    void testGetSourcesNonExistentDir() throws Exception {
+    public void testGetSourcesNonExistentDir() throws Exception {
 
         // given
 
@@ -299,7 +302,7 @@
     }
     
     @Test
-    void testLastModified() throws Exception {
+    public void testLastModified() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/sources/DirModeTest.java
+++ b/src/test/java/ch/artecat/grengine/sources/DirModeTest.java
@@ -16,16 +16,19 @@
 
 package ch.artecat.grengine.sources;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class DirModeTest {
+public class DirModeTest {
+
+    public DirModeTest() {
+    }
 
     @Test
-    void testValueOf() {
+    public void testValueOf() {
 
         // when/then
 
@@ -34,7 +37,7 @@
     }
     
     @Test
-    void testValues() {
+    public void testValues() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/sources/FixedSetSourcesTest.java
+++ b/src/test/java/ch/artecat/grengine/sources/FixedSetSourcesTest.java
@@ -24,7 +24,7 @@
 
 import java.util.Set;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -33,10 +33,13 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class FixedSetSourcesTest {
+public class FixedSetSourcesTest {
+
+    public FixedSetSourcesTest() {
+    }
 
     @Test
-    void testConstructDefaults() throws Exception {
+    public void testConstructDefaults() throws Exception {
 
         // given
 
@@ -65,7 +68,7 @@
     }
     
     @Test
-    void testConstructAllDefined() throws Exception {
+    public void testConstructAllDefined() throws Exception {
 
         // given
 
@@ -98,7 +101,7 @@
     }
     
     @Test
-    void testConstructSourceSetNull() {
+    public void testConstructSourceSetNull() {
 
         // when/then
 
@@ -108,7 +111,7 @@
     }
     
     @Test
-    void testModifyBuilderAfterUse() {
+    public void testModifyBuilderAfterUse() {
 
         // given
 
@@ -126,7 +129,7 @@
     }
     
     @Test
-    void testLastModified() throws Exception {
+    public void testLastModified() throws Exception {
 
         // given
 
--- a/src/test/java/ch/artecat/grengine/sources/SourcesUtilTest.java
+++ b/src/test/java/ch/artecat/grengine/sources/SourcesUtilTest.java
@@ -23,7 +23,7 @@
 
 import java.util.HashSet;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 import static ch.artecat.grengine.TestUtil.assertThrowsMessageIs;
 import static org.hamcrest.CoreMatchers.instanceOf;
@@ -32,15 +32,18 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 
 
-class SourcesUtilTest {
+public class SourcesUtilTest {
+
+    public SourcesUtilTest() {
+    }
 
     @Test
-    void testConstructor() {
+    public void testConstructor() {
         new SourcesUtil();
     }
 
     @Test
-    void testSourceToSourcesDefaultCompilerFactory() {
+    public void testSourceToSourcesDefaultCompilerFactory() {
 
         // given
 
@@ -60,7 +63,7 @@
     }
 
     @Test
-    void testSourceToSourcesDefaultCompilerFactorySourceNull() {
+    public void testSourceToSourcesDefaultCompilerFactorySourceNull() {
 
         // when/then
 
@@ -70,7 +73,7 @@
     }
 
     @Test
-    void testSourceToSourcesSpecificCompilerFactory() {
+    public void testSourceToSourcesSpecificCompilerFactory() {
 
         // given
 
@@ -90,7 +93,7 @@
     }
     
     @Test
-    void testSourceToSourcesSpecificCompilerFactorySourceNull() {
+    public void testSourceToSourcesSpecificCompilerFactorySourceNull() {
 
         // when/then
 
@@ -100,7 +103,7 @@
     }
     
     @Test
-    void testSourceToSourcesSpecificCompilerFactoryNull() {
+    public void testSourceToSourcesSpecificCompilerFactoryNull() {
 
         // when/then
 
@@ -111,7 +114,7 @@
 
     
     @Test
-    void testSourceSetToSourcesDefaultCompilerFactory() {
+    public void testSourceSetToSourcesDefaultCompilerFactory() {
 
         // given
 
@@ -133,7 +136,7 @@
     }
 
     @Test
-    void testSourceSetToSourcesDefaultCompilerFactorySourceSetNull() {
+    public void testSourceSetToSourcesDefaultCompilerFactorySourceSetNull() {
 
         // when/then
 
@@ -143,7 +146,7 @@
     }
 
     @Test
-    void testSourceSetToSourcesDefaultCompilerFactorySourceNameNull() {
+    public void testSourceSetToSourcesDefaultCompilerFactorySourceNameNull() {
 
         // when/then
 
@@ -153,7 +156,7 @@
     }
     
     @Test
-    void testSourceSetToSourcesSpecificCompilerFactory() {
+    public void testSourceSetToSourcesSpecificCompilerFactory() {
 
         // given
 
@@ -176,7 +179,7 @@
     }
 
     @Test
-    void testSourceSetToSourcesSpecificCompilerFactorySourceSetNull() {
+    public void testSourceSetToSourcesSpecificCompilerFactorySourceSetNull() {
 
         // when/then
 
@@ -187,7 +190,7 @@
     }
 
     @Test
-    void testSourceSetToSourcesSpecificCompilerFactorySourceNameNull() {
+    public void testSourceSetToSourcesSpecificCompilerFactorySourceNameNull() {
 
         // when/then
 
@@ -198,7 +201,7 @@
     }
 
     @Test
-    void testSourceSetToSourcesSpecificCompilerFactoryNull() {
+    public void testSourceSetToSourcesSpecificCompilerFactoryNull() {
 
         // when/then
 
--- a/src/test/java/ch/artecat/grengine/source/MockFile.java
+++ b/src/test/java/ch/artecat/grengine/source/MockFile.java
@@ -22,7 +22,7 @@
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.Assert.fail;
 
 
 // so far, mocks only last modified
--- a/src/test/java/ch/artecat/grengine/source/MockFileSource.java
+++ b/src/test/java/ch/artecat/grengine/source/MockFileSource.java
@@ -19,7 +19,7 @@
 import java.io.File;
 import java.io.IOException;
 
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.Assert.fail;
 
 
 // so far, mocks only last modified
--- a/src/test/java/ch/artecat/grengine/engine/EngineConcurrencyTestFrame.java
+++ b/src/test/java/ch/artecat/grengine/engine/EngineConcurrencyTestFrame.java
@@ -26,6 +26,7 @@
 import static ch.artecat.grengine.TestUtil.toRuntimeException;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.fail;
 
 
 public class EngineConcurrencyTestFrame {
