public Sequence eval(DocumentSet docs, Sequence contextSequence, Item contextItem) throws XPathException {
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
    public Sequence eval(DocumentSet docs, Sequence contextSequence, Item contextItem) throws XPathException {		if(contextSequence == null || contextSequence.getLength() == 0)			return Sequence.EMPTY_SEQUENCE;		return new IntegerValue(context.getContextPosition() + 1);    }