@Test
public void testGetNumUsersWithDelegateUsersOnly() throws TasteException {

   PreferenceArray prefs = new GenericUserPreferenceArray(1);
   long sampleUserID = 1;
	prefs.setUserID(0, sampleUserID);
   long sampleItemID = 11;
   prefs.setItemID(0, sampleItemID);
	FastByIDMap<PreferenceArray> delegatePreferences = new FastByIDMap<PreferenceArray>();
	delegatePreferences.put(sampleUserID, prefs);
	PlusAnonymousConcurrentUserDataModel instance = getTestableWithDelegateData(10, delegatePreferences);
	assertEquals(1, instance.getNumUsers());
}