Is it possible to insert a comment tag into an xml using simplexml?

Question

I am using SimpleXML to build a document, and wondering whether it is possible to insert comment tag to the document like this:

When using $root->asXML() you'd get a string like this:

You may notice it generated an empty element as well, but it's the price to pay. Don't try to add a value, it would only mess everything up. Use only in conjunction with asXML().

Well, I did say it's a dirty trick. I don't recommend using this in production, but only for debugging/testing purposes.