Set<RefClass> (RefClass refClass) { final Set<RefClass> dependencies = refClass.getUserData(TRANSITIVE_DEPENDENCY_CLASSES_KEY); if (dependencies != null) { return dependencies; } final Set<RefClass> newDependencies = new HashSet<>(); tabulateTransitiveDependencyClasses(refClass, newDependencies); refClass.putUserData(TRANSITIVE_DEPENDENCY_CLASSES_KEY, newDependencies); return newDependencies; }