throw new XPathException("Empty sequence is not allowed here");
throw new XPathException(getASTNode(), "Empty sequence is not allowed here");
	public Sequence eval(		Sequence contextSequence,		Item contextItem)		throws XPathException {		Sequence seq = expression.eval(contextSequence, contextItem);		int items = seq.getLength();		if(items > 0 && requiredCardinality == Cardinality.EMPTY)			throw new XPathException("Empty sequence expected; got " + items);		if(items == 0 && (requiredCardinality & Cardinality.ZERO) == 0)			throw new XPathException("Empty sequence is not allowed here");		else if(items > 1 && (requiredCardinality & Cardinality.MANY) == 0)			throw new XPathException("Sequence with more than one item is not allowed here");		return seq;	}