public Sequence eval(StaticContext context, DocumentSet docs, Sequence contextSequence, Item contextItem) throws XPathException {
public Sequence eval(DocumentSet docs, Sequence contextSequence, Item contextItem) throws XPathException {
	public Sequence eval(StaticContext context, DocumentSet docs, Sequence contextSequence,		Item contextItem) throws XPathException {		if(contextItem != null)			contextSequence = contextItem.toSequence();		String strval = getArgument(0).eval(context, docs, contextSequence).getStringValue();		return new IntegerValue(strval.length());	}