def _reset(self):
        """
        This method is for use by tests only!
        """
        self.bundles = AttrDict()
        self._bundles = _DeferredBundleFunctionsStore()
        self.babel_bundle = None
        self.env = None
        self.extensions = AttrDict()
        self.services = AttrDict()

        self._deferred_functions = []
        self._initialized = False
        self._models_initialized = False
        self._services_initialized = False
        self._services_registry = {}
        self._shell_ctx = {}
This method is for use by tests only!