Am using Odoo10 customized in file web\static\src\js\views\form_view.js as below method:

  form_view.js

      odoo.define('web.FormRenderingEngine', function (require) {

       "use strict";

       process_group: function($group) {

              // custom Code

      }

   });

Am extending this file like as mention below: 

var FormRenderingEngine = require('web.FormRenderingEngine');

return FormRenderingEngine.extend({

  process_group: function($group) {   // custom Code

}

}};

.extend or include doesn't work.

please anyone help me to resolve this.