code: function (aggId, cmd) {
      if (!aggId || !_.isString(aggId)) {
        var err = new Error('Please pass a valid aggregate id!');
        debug(err);
        throw err;
      }
  
      _.remove(this.queue[aggId], function (c) {
        return c.command === cmd;
      });
    }
docs: Removes the passed command from the queue.
  @param {String} aggId The passed aggregate id.
  @param {Object} cmd   The command to be queued.