@spalger/kibana/src/plugins/kibana/public/visualize/editor/advanced_toggle.html

Kibana is an open source (Apache Licensed), browser based analytics and search dashboard for Elasticsearch. Kibana is a snap to setup and start using. Kibana strives to be easy to get started with, while also being flexible and powerful, just like Elastic

<div class="vis-editor-agg-editor-advanced-toggle">
  <a ng-click="advancedToggled = !advancedToggled">
    <i aria-hidden="true" class="fa fa-caret-down" ng-class="{'fa-caret-down': advancedToggled, 'fa-caret-left': !advancedToggled}"></i>
    Advanced
  </a>
</div>