discourse/app/assets/javascripts/admin/models/email-template.js.es6

import RestModel from 'discourse/models/rest';

const { getProperties } = Ember;
console.log(getProperties);

export default RestModel.extend({
  revert() {
    return Discourse.ajax(`/admin/customize/email_templates/${this.get('id')}`, {
      method: 'DELETE'
    }).then(result => getProperties(result.email_template, 'subject', 'body', 'can_revert'));
  }
});