code: public function getBreadcrumbsArray($menu, $subItem = null)
      {
          if (null === $this->menuManipulator) {
              throw new \BadMethodCallException('The menu manipulator must be set to get the breadcrumbs array');
          }
  
          $menu = $this->castMenu($menu);
  
          return $this->menuManipulator->getBreadcrumbsArray($menu, $subItem);
      }
docs: Renders an array ready to be used for breadcrumbs.
  
  Each element in the array will be an array with 3 keys:
  - `label` containing the label of the item
  - `url` containing the url of the item (may be `null`)
  - `item` containing the original item (may be `null` for the extra items)
  
  The subItem can be one of the following forms
  * 'subItem'
  * ItemInterface object
  * array('subItem' => '@homepage')
  * array('subItem1', 'subItem2')
  * array(array('label' => 'subItem1', 'url' => '@homepage'), array('label' => 'subItem2'))
  
  @param mixed $item
  @param mixed $subItem A string or array to append onto the end of the array
  
  @return array