Return the rooms a client is in.

def get_rooms(self, sid, namespace):
        """Return the rooms a client is in."""
        r = []
        try:
            for room_name, room in six.iteritems(self.rooms[namespace]):
                if room_name is not None and sid in room and room[sid]:
                    r.append(room_name)
        except KeyError:
            pass
        return r