/**
  * {@inheritdoc}
  */
 public function getFormId()
 {
     return 'entity_browser_' . $this->entity_browser->id() . '_form';
 }
 /**
  * Registers JS callback that gets entities from entity browser and updates
  * form values accordingly.
  */
 public function registerJSCallback(RegisterJSCallbacks $event)
 {
     if ($event->getBrowserID() == $this->entityBrowser->id()) {
         $event->registerCallback('Drupal.entityEmbedDialog.selectionCompleted');
     }
 }