code: function (appName, queueName, redisOptions, callback) {
      if (_.isFunction(redisOptions)) {
          callback = redisOptions;
          redisOptions = undefined;
      }
      var msgQueueName = _setMsgQueueName(appName, queueName);
      if (_.isFunction(callback)) {
          // Return an existing msg queue (if one exists)
          return _getMsgQueue(msgQueueName, function (error, msgQueue) {
              if (!error) {
                  // Return the existing msg queue
                  return callback(undefined, msgQueue);
              }
              // Create and return a new msg queue
              return callback(undefined, new RedisMsgQueue(appName, queueName, redisOptions));
          })
      }
      // Return an existing msg queue (if one exists)
      var msgQueue = _getMsgQueue(msgQueueName);
      if (msgQueue) {
          // Return the existing msg queue
          return msgQueue;
      }
      // Create and return a new msg queue
      return new RedisMsgQueue(appName, queueName, redisOptions);
  }
docs: ---------------------------------------------------------------------------------------------------- The msg queue class factory methods and the msg queue class ----------------------------------------------------------------------------------------------------