def __init__(self, mapper=None):
<EOL>self.wsgi_actions = dict((k, getattr(self, k))<EOL>for k in self._wsgi_actions)<EOL>self.wsgi_extensions = dict((k, [getattr(self, k)])<EOL>for k in self._wsgi_extensions)<EOL>self.wsgi_descriptors = {}<EOL>self.wsgi_mapper = mapper<EOL>if mapper:<EOL><INDENT>for action, route in self.wsgi_actions.items():<EOL><INDENT>self._route(action, route)<EOL><DEDENT><DEDENT>
Initialize a Controller subclass.  The `mapper` argument is
used by the Application class to specify the Routes mapper
being constructed.