assertNotNull("Document iterator has one element", documentIterator);
assertTrue("Document iterator has one element", documentIterator.hasNext());
Object next = documentIterator.next();
assertNotNull("Document iterator has one element", next);
assertTrue("Document iterator has one element", next instanceof IDocument);
IDocument document = (IDocument) next;
assertEquals("Document named", "MANIFEST.MF", document.getName());
Iterator subsubcollectionIterator = subcollection.subcollectionIterator();
assertNotNull("No sub collections", subsubcollectionIterator);
assertFalse("No sub collections", subsubcollectionIterator.hasNext());
}