How to get raw markup for an org.w3c.Node

Question

Possible Duplicate:
How to I output org.w3c.dom.Element to string format in java?

I have an xml snippet, like

    <div>
        <span>     
            <a href="http://someUrl.com"&gt;Cool site, bro!</a>  
        </span>    
    </div>

And an org.w3c.dom.Node, corresponding to my div element. How do I get a Node's String representation, that contains raw markup? I.e. I want to get

Node node = (Node) myXpathExpression.evaluate(document, XPathConstants.NODE);
String rawMarkup = getRawMarkup(node);
assertEquals("\n\t\t<span>\n\t\t\t<a href=\"http://someUrl.com\"&gt;Cool site, bro!</a>\n\t\t</span>\n\t", rawMarkup)

Also, what is the best strategy if I want to filter out some tags (e.g. , etc.) and get raw markup without them?