Document::saveHTML

public function saveHTML(Node $node = null)
{
	if($node === null)
	{
		$result = '';

		if(self::$isNodeListAsArray)
		{
			$childNodes = $this->getChildNodesArray();
			foreach ($childNodes as $child)
			{
				/** @var $child Node */
				$result .= $child->getOuterHTML();
			}
		}
		else
		{
			for($i = 0; $i < $this->getChildNodes()->getLength(); $i++)
			{
				$child = $this->getChildNodes()->item($i);
				/** @var $child Node */
				if($child)
				{
					$result .= $child->getOuterHTML();
				}
			}
		}

		return $result;
	}
	else
	{
		return $node->getOuterHTML();
	}
}