* obj is an instanceof Node then create a singleton iterator.
*/
public static DTMAxisIterator referenceToNodeSet(Object obj) {
// Convert var/param -> node
if (obj instanceof Node) {
return(new SingletonIterator(((Node)obj).node));
}
// Convert var/param -> node-set
else if (obj instanceof DTMAxisIterator) {
return(((DTMAxisIterator)obj).cloneIterator().reset());
}