@Override
 public void commit(DatabaseServer databaseObject) {
   SessionServer sessionServer = (SessionServer) databaseObject;
   sessionServer.gid = gid;
   super.commit(databaseObject);
 }
 /** @return a list of the player in this session */
 public ArrayList<String> getPlayers() {
   SessionServer sessionServer = SessionServer.fetch(getGamePersistenceManagerServer(), getKey());
   return null == sessionServer ? new ArrayList<String>() : sessionServer.getList();
 }