Retrieve records from Azure Service Bus queue but not deleting data

I followed below sample from "https://github.com/noodlefrenzy/node-amqp10" to retrieve records from Azure Service Bus queue.  However, all data were deleted after run the code. 

const AMQPClient = require('amqp10').Client;
const Policy = require('amqp10').Policy;

const protocol = 'amqps';
const keyName = 'RootManageSharedAccessKey';
const sasKey = 'your_key_goes_here';
const serviceBusHost = 'namespace.servicebus.windows.net';
const uri = `${protocol}://${encodeURIComponent(keyName)}:${encodeURIComponent(sasKey)}@${serviceBusHost}`;
const queueName = 'partitionedQueueName';
const client = new AMQPClient(Policy.ServiceBusQueue);

client.connect(uri)
.then(() => Promise.all([client.createReceiver(queueName)]))
.spread((receiver) => {
    console.log('--------------------------------------------------------------------------');
    receiver.on('errorReceived', (err) => {
        // check for errors
        console.log(err);
    });
    receiver.on('message', (message) => {
        console.log('Received message');
        console.log(message);
        console.log('----------------------------------------------------------------------------');
    });
})
.error((e) => {
    console.warn('connection error: ', e);
});

I did a research and found out that I need to add "receiverSettleMode" to the value "Constants.receiverSettleMode.settleOnDisposition" within"client.createReceiver" function. So added following code before "client.connect(uri)":
const { Constants }= require('amqp10');

Updated the "client.createReceiver" function to

client.createReceiver(queueName, {

attach: {

rcvSettleMode: Constants.receiverSettleMode.settleOnDisposition

}

})

Execute the code and it works! All records are still there after processing.

To learn more about "Azure Solution Development", see this course"70-534 Architecting Microsoft Azure Solutions Certification"