code: public function getSubMenu($nodeId, $nbLevel, $language, $siteId)
      {
          $node = $this->findOnePublished($nodeId, $language, $siteId);
          $list = array();
  
          if ($node instanceof ReadNodeInterface) {
              $list[] = $node;
              $list = array_merge($list, $this->getTreeParentIdLevelAndLanguage($node->getNodeId(), $nbLevel, $language, $siteId));
          }
  
          return $list;
      }
docs: @param string $nodeId
  @param int    $nbLevel
  @param string $language
  @param string $siteId
  
  @return array