NodeSet result = ((NodeSet)lval).intersection((NodeSet)rval);
NodeSet result = lval.toNodeSet().intersection(rval.toNodeSet());
	public Sequence eval(Sequence contextSequence, Item contextItem)		throws XPathException {			Sequence lval = left.eval(contextSequence, contextItem);			Sequence rval = right.eval(contextSequence, contextItem);			if(lval.getItemType() != Type.NODE || rval.getItemType() != Type.NODE)				throw new XPathException("intersect operand is not a node sequence");			NodeSet result = ((NodeSet)lval).intersection((NodeSet)rval);			return result;	}