docs: function execute(cmd, args, cb) {
    if(typeof args === 'function') {
      cb = args;
      args = null;
    }
    var arr = [cmd].concat(args || []);
    if(typeof cb === 'function') {
      this.once('reply', cb);
    }
  
    // sending over tcp
    if(this.tcp) {
      this.encoder.write(arr);
    // connected to a server within this process
    }else{
      this.socket.write(arr);
    }
  }