code: def join_room(self, room_id_or_alias):
          
          response = self.api.join_room(room_id_or_alias)
          room_id = (
              response["room_id"] if "room_id" in response else room_id_or_alias
          )
          return self._mkroom(room_id)
docs: Join a room.
  
          Args:
              room_id_or_alias (str): Room ID or an alias.
  
          Returns:
              Room
  
          Raises:
              MatrixRequestError