@Override
  public synchronized @NotNull Set<RefClass> getBaseClasses() {
    if (myBases == null) return EMPTY_CLASS_SET;
    //noinspection unchecked
    return myBases instanceof Set ? (Set<RefClass>)myBases : Collections.singleton((RefClass)myBases);
  }
@Override
  public synchronized @NotNull Set<RefClass> getBaseClasses()