/**
  * {@inheritdoc}
  */
 public function viewMultiple(array $entities = array(), $view_mode = 'full', $langcode = NULL)
 {
     $build_list = parent::viewMultiple($entities, $view_mode, $langcode);
     // Apply the buildMultiple() #pre_render callback immediately, to make
     // bubbling of attributes and contextual links to the actual block work.
     // @see \Drupal\block\BlockViewBuilder::buildBlock()
     unset($build_list['#pre_render'][0]);
     return $this->buildMultiple($build_list);
 }