import com.thoughtworks.xstream.XStream;


public class XStreamBug {

	private static class Bug {
		private long _underscored;
	}
	public static void main(String[] args) throws Exception {
		XStream xs = new XStream();
        xs.useAttributeFor(long.class);  // Make _underscore an attribute
        xs.setMode(XStream.ID_REFERENCES);
		String xml = xs.toXML(new Bug());
		Bug bug = (Bug)xs.fromXML(xml);  // Gets exception 

	}
}