code: protected function getChildren($parentId, array $nodes)
      {
          $children = array();
          foreach ($nodes as $position => $node) {
              if ($parentId === $node['node']['parentId']) {
                  unset($nodes[$position]);
                  $children[] = array('node' => $node['node'], 'child' => $this->getChildren($node['nodeId'], $nodes));
              }
          }
          uasort($children, array($this, 'sortTree'));
          $children = array_values($children);
  
          return $children;
      }
docs: @param string $parentId
  @param array  $nodes
  
  @return array