code: function reply(id, args) {
    var msg = new Array(2 + args.length);
  
    msg[0] = '_reply_';
    msg[1] = id;
  
    for (var i = 0; i < args.length; i++) {
      msg[i + 2] = args[i];
    }
  
    return msg;
  }
docs: Return a reply message for `id` and `args`.
  
  @param {String} id
  @param {Array} args
  @return {Array}
  @api private