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();		NumericValue value = (NumericValue)			getArgument(0).eval(context, docs, contextSequence, contextItem).convertTo(Type.NUMBER); 		return new DoubleValue(Math.ceil(value.getDouble()));	}