REQ: DOMDocument needs a way to format XML code

I have a feature request (and I'm a bit disappointed that this isn't already in the DOMDocument, when there are nearly useless methods like "normalize()")... Ruby has this built in. xmllint has the --format parameter. But yet PHP's DOMDocument has no way of cleaning up the code. Could someone please make a method in PHP v5.x to format the XML. After adding/deleting nodes, the XML gets fairly messy. Ideally it would have an offset character position to start the indent (default of 0 or left margin), and a parameter for how many spaces to use for each indentation (default of say 4 or 5 (same as a tab)). You could just make this optional parameters to saveXML(), but I think it's more flexible to have a DOMDocument->format(offset,spaces);