.js

function(){
    // prevent double callbacks
    if (sent) return;
    var args = Array.prototype.slice.call(arguments);
    debug('sending ack %j', args);

    self.packet({
      id: id,
      type: hasBin(args) ? parser.BINARY_ACK : parser.ACK,
      data: args
    });

    sent = true;
  }