How to use the ember-power-select/components/power-select/trigger.extend function in ember-power-select

/**
 * @module ember-paper
 */
import { computed } from '@ember/object';

import TriggerComponent from 'ember-power-select/components/power-select/trigger';
import layout from '../templates/components/paper-select-trigger';

/**
 * @class PaperSelectTrigger
 * @extends Ember.Component
 */
export default TriggerComponent.extend({
  layout,
  tagName: 'md-select-value',
  classNames: ['md-select-value'],
  classNameBindings: ['isPlaceholder:md-select-placeholder'],
  isPlaceholder: computed('placeholder', 'label', 'select.selected', function() {
    return (this.get('placeholder') || this.get('label')) && !this.get('select.selected');
  })
});

/**
 * @module ember-paper
 */
import Ember from 'ember';
import TriggerComponent from 'ember-power-select/components/power-select/trigger';
import layout from '../templates/components/paper-select-trigger';

const { computed } = Ember;

/**
 * @class PaperSelectTrigger
 * @extends Ember.Component
 */
export default TriggerComponent.extend({
  layout,
  tagName: 'md-select-value',
  classNames: ['_md-select-value'],
  classNameBindings: ['isPlaceholder:_md-select-placeholder'],
  isPlaceholder: computed('placeholder', 'label', 'select.selected', function() {
    return (this.get('placeholder') || this.get('label')) && !this.get('select.selected');
  })
});