return view.extend({
  load: function() {
    return new Promise(function(resolveFn, rejectFn) {
      document.querySelector('head').appendChild(E('script', {
        src: 'blah.js',
        load: resolveFn,
        error: rejectFn
      }));
    });
  },
  render: function() {
    ...
  }
});