How can I extend the Consumer object without touching the core code? about sqs-consumer HOT 2 CLOSED

var app = [];
Consumer.prototype.setExtraProperties = function(extraProperties) {
    this.extraProperties = extraProperties;
}

var Consumer1 = new Consumer({
  queueUrl: `https://sqs.ap-southeast-1.amazonaws.com/QNAME1`,
  handleMessage: handleMessage,
  sqs: new AWS.SQS(),
  batchSize: 10,
});

Consumer1.setExtraProperties({version:1});
Consumer1._processMessageBound = _processMessage.bind(Consumer1);
app.push(Consumer1);

var Consumer2 = new Consumer({
  queueUrl: `https://sqs.ap-southeast-1.amazonaws.com/QNAME2`,
  handleMessage: handleMessage,
  sqs: new AWS.SQS(),
  batchSize: 10,
});

Consumer2.setExtraProperties({version:2});
Consumer2._processMessageBound = _processMessage.bind(Consumer2);
app.push(Consumer2);

if (app.length > 0) {
  let consumer;
  for (let i in app) {
    consumer = app[i];
    consumer.on('error', err => {
      console.error(`error on app:  ${err.message}`);
      console.log('The app will restart due to error');
      setTimeout( () => {
        process.exit(1);
      }, 3000);
    });

    consumer.on('processing_error', err => {
      console.error(`processing_error on app:  ${err.message}`);
      console.log('The app will restart due to processing_error');
      setTimeout( () => {
        process.exit(1);
      }, 3000);
    });

    consumer.start();
  }
}

function _processMessage (message, cb) {
  var consumer = this;

  this.emit('message_received', message);
  async.series([
    function handleMessage(done) {
      consumer.handleMessage(message, done, consumer.extraProperties);
    },
    function deleteMessage(done) {
      consumer._deleteMessage(message, done);
    }
  ], function (err) {
    if (err) {
      if (err.name === SQSError.name) {
        consumer.emit('error', err, message);
      } else {
        consumer.emit('processing_error', err, message);
      }
    } else {
      consumer.emit('message_processed', message);
    }
    cb();
  });
}