code: function tryToGetClient(clientId) {
      var clientObj;
      try {
          clientObj = this.clients.get(clientId);
      }
      catch(e) {
          this.channel.sysLogger.log("GameRoom.setupGame: no client with id '" +
                                     clientId + "'", 'warn');
      }
      return clientObj;
  }
docs: ### tryToGetClient
  
  Returns a client obj with given id, if found.
  
  Notice: separated from the main function because of the try-catch block,
  otherwise the whole function is not optimized.
  
  @param {string} clientId The client id
  
  @return {object} The client object