/**
  * Constructor
  * @param BasicNode $node
  * @throws \InvalidArgumentException
  */
 public function __construct(BasicNode $node)
 {
     $this->node = $node;
     $subnodes = $node->getNodes();
     if (is_object($subnodes)) {
         $this->nodes[] = $subnodes;
     } else {
         if (is_array($subnodes)) {
             $this->nodes = $subnodes;
         }
     }
 }