Issue373.java:16:15: compiler.err.proc.messager: [override.return.invalid] Incompatible return type.
Method
  Set<Entry<String, String>> entrySet(Issue373 this) in Issue373
cannot override
  Set<Entry<@KeyFor("this") String, String>> entrySet(AbstractMap<String, String> this) in java.util.AbstractMap
found   : Set<Entry<String, String>>
required: Set<Entry<@KeyFor("this") String, String>>
1 error
