throw new XPathException(arg.getStringValue());
throw new XPathException(getASTNode(), arg.getStringValue());
	public Sequence eval(Sequence contextSequence, Item contextItem)		throws XPathException {		Sequence arg = getArgument(0).eval(contextSequence, contextItem);		if (arg.getLength() == 0)			throw new XPathException();		else			throw new XPathException(arg.getStringValue());	}