Mako Runtime Error

## Error !

### AttributeError: 'builtin_function_or_method' object has no attribute 'show_title'

5 <head>
6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
7 ${metatags and metatags or ''}
8 <title>${capture(next.show_title)|util.striptags} &mdash; ${docstitle|h}</title>
9 ${self.headers()}
10 <!-- <link rel="stylesheet" href="http://www.myjqueryplugins.com/plugins/jmenu/demo/jquery/jMenu.jquery.css" type="text/css" /> -->
11 <link rel="stylesheet" href="${pathto('_static/jMenu.jquery.css', 1)}" type="text/css" />
12
13 <!-- <script type="text/javascript" src="http://www.myjqueryplugins.com/plugins/jmenu/demo/jquery/jMenu.jquery.js"></script> -->
templates/static_base.mako, line 8:
<title>${capture(next.show_title)|util.striptags} &mdash; ${docstitle|h}</title>
/misc/src/mako/lib/mako/runtime.py, line 333:
callable_(context, *args, **kwargs)