docs: MeetMeRoomImpl getOrCreateRoomImpl(String roomNumber)
      {
          MeetMeRoomImpl room;
          boolean created = false;
  
          synchronized (rooms)
          {
              room = rooms.get(roomNumber);
              if (room == null)
              {
                  room = new MeetMeRoomImpl(server, roomNumber);
                  populateRoom(room);
                  rooms.put(roomNumber, room);
                  created = true;
              }
          }
  
          if (created)
          {
              logger.debug("Created MeetMeRoom " + roomNumber);
          }
  
          return room;
      }