ret.retainAll(distinctEnumerizableElementSets);
// make sure the fields have a consistent visibility.
final Collection consistentEnumerizableElementSets = Util
.getConsistentlyVisibleSets(candidateSets);
ret.retainAll(consistentEnumerizableElementSets);
// make sure the fields are named uniquely.
final Collection uniquelyNamedEnumerizableElementSets = Util
.getUniquelyNamedSets(candidateSets);
ret.retainAll(uniquelyNamedEnumerizableElementSets);