what is amqp10 policy nodejs

var AMQPClient = require('amqp10').Client,
    Promise = require('bluebird');

var client = new AMQPClient(); // Uses PolicyBase default policy
client.connect('amqp://localhost')
  .then(function() {
    return Promise.all([
      client.createReceiver('amq.topic'),
      client.createSender('amq.topic')
    ]);
  })
  .spread(function(receiver, sender) {
    receiver.on('errorReceived', function(err) { // check for errors });
    receiver.on('message', function(message) {
      console.log('Rx message: ', message.body);
    });

    return sender.send({ key: "Value" });
  })
  .error(function(err) {
    console.log("error: ", err);
  });