'Return self if we should be used to import the module.'

def find_module(self, fullname, path=None):

    if fullname.startswith((self.src + '.')):
        mirror_name = self._mirror_name(fullname)
        try:
            mod = import_item(mirror_name)
        except ImportError:
            return
        else:
            if (not isinstance(mod, types.ModuleType)):
                return None
            return self
