what is amqp10 policy nodejs

1var AMQPClient = require('amqp10').Client,
2    Promise = require('bluebird');
3
4var client = new AMQPClient(); // Uses PolicyBase default policy
5client.connect('amqp://localhost')
6  .then(function() {
7    return Promise.all([
8      client.createReceiver('amq.topic'),
9      client.createSender('amq.topic')
10    ]);
11  })
12  .spread(function(receiver, sender) {
13    receiver.on('errorReceived', function(err) { // check for errors });
14    receiver.on('message', function(message) {
15      console.log('Rx message: ', message.body);
16    });
17
18    return sender.send({ key: "Value" });
19  })
20  .error(function(err) {
21    console.log("error: ", err);
22  });
23