protected Sequence nodeSetCompare(DocumentSet docs, Sequence contextSequence)
protected Sequence nodeSetCompare(Sequence contextSequence)
	protected Sequence nodeSetCompare(DocumentSet docs, Sequence contextSequence)		throws XPathException {		// evaluate left expression (returning node set)		NodeSet nodes = (NodeSet) getLeft().eval(docs, contextSequence);		return nodeSetCompare(nodes, docs, contextSequence);	}