roit.hasNext();
roit.next();
// check derived collections are still read only and share the same
// challenge policy
SecuredFeatureCollection sorted = (SecuredFeatureCollection) rofc
.sort(SortBy.NATURAL_ORDER);
assertEquals(ro.policy, sorted.policy);
SecuredFeatureCollection sub = (SecuredFeatureCollection) rofc
.subCollection(Filter.INCLUDE);
assertEquals(ro.policy, sorted.policy);