protected function serializeChildren(DOMElement $ir)
	{
		$php = '';
		foreach ($ir->childNodes as $node)
		{
			if ($node instanceof DOMElement)
			{
				$methodName = 'serialize' . ucfirst($node->localName);
				$php .= $this->$methodName($node);
			}
		}

		return $php;
	}