public function findTreeItem($id, MapperTreeItemInterface $item)
    {
        if ($id === $item->getId()) {
            return $item;
        }
        foreach ($item->getChildren() as $child) {
            if (null !== $treeItem = $this->findTreeItem($id, $child)) {
                return $treeItem;
            }
        }

        return null;
    }