static Set<S> nonStaticNonTransientFields_withoutSuperclasses(O o) {
  new TreeSet<S> fields;
  Class _c = _getClass(o);
  if (_c != null) for (Field f : _c.getDeclaredFields())
    if ((f.getModifiers() & (Modifier.STATIC|Modifier.TRANSIENT)) == 0)
      fields.add(f.getName());
  ret fields;
}