<div ui-tree-handle>
  <div class="field" style="width:100%;">
    <md-button ng-click="toggle_related_fields(this)"> + </md-button>
    <span ng-click="load_fields(field)">{{field.verbose_name}}</span>
  </div>
</div>
<ol ui-tree-nodes="" ng-model="field.related_fields" ng-class="{hidden: collapsed}">
  <li ng-repeat="field in field.related_fields | filter:searchRelations" ui-tree-node ng-include="static('report_builder/partials/node_renderer.html')">
  </li>
</ol>
