Attempts to load plugin modules according to the order of available
            plugin directories.

def _load_plugins(self):
        """ Attempts to load plugin modules according to the order of available
            plugin directories.
            """

        # import base plugin modules
        try:
            __import__('focus.plugin.modules')
            #import focus.plugin.modules
        except ImportError as exc:
            raise errors.PluginImport(unicode(exc))

        # load user defined plugin modules
        try:
            user_plugin_dir = os.path.join(self._data_dir, 'plugins')
            _import_modules(user_plugin_dir)

        except Exception as exc:
            raise errors.UserPluginImport(unicode(exc))