code: def join_room(self, room_name):   
               
          logging.debug('Joining room {ro}'.format(ro=room_name))
  
          for room in self.rooms:
              if room.name == room_name:
                  room.add_user(self)
                  self._rooms[room_name] = room
                  room.welcome(self)
                  break
          else:
              room = Room(room_name)
              self.rooms.append(room)
              self._rooms[room_name] = room
              room.add_user(self)
docs: Connects to a given room 
                  If it does not exist it is created