static Set<RefClass> calculateTransitiveDependenciesForClass(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;
  }
static Set<RefClass> calculateTransitiveDependenciesForClass(RefClass refClass)