Leave a room

def leave(self, _id):
        """ Leave a room """
        if SockJSRoomHandler._room.has_key(self._gcls() + _id):
            SockJSRoomHandler._room[self._gcls() + _id].remove(self)
            if len(SockJSRoomHandler._room[self._gcls() + _id]) == 0:
                del SockJSRoomHandler._room[self._gcls() + _id]