'Store old routes and apply new one'

def enter(self):

    for alias in self._aliases:
        channel_layer = channel_layers[DEFAULT_CHANNEL_LAYER]
        self._old_routing[alias] = channel_layer.routing
        if isinstance(self.routes, (list, tuple)):
            if isinstance(self.routes[0], (list, tuple)):
                routes = list(map(include, self.routes))
            else:
                routes = self.routes
        else:
            routes = [self.routes]
        channel_layer.routing = routes
        channel_layer.router = Router(routes)
