public function addChild(self $node)
	{
		$index = count($this->node_children);
		$this->insertChildAt($index, $node);
	}
public function addChild(self $node)
	{
		$index = count($this->node_children);
		$this->insertChildAt($index, $node);
	}
public function addChild ( self $ node ) { $ index = count ( $ this -> node_children ) ; $ this -> insertChildAt ( $ index , $ node ) ; }
Add the given node at the end.
@param self $node
@return self
Add the given node at the end .