What does this function does ? Magento 2 billing-address.js

Question

Would like to know what does this fucntion does in billing-address.js
initialize: function () { this._super(); quote.paymentMethod.subscribe(function () { checkoutDataResolver.resolveBillingAddress(); }, this); shippingRatesValidator.initFields(this.get('name') + '.form-fields'); },

Answer 1

Code written in this function will execute first