static Map<S, Field> nonStaticFieldsMap(Class _c) {
  new HashMap<S, Field> fields;
  do {
    for (Field f : _c.getDeclaredFields())
      if ((f.getModifiers() & Modifier.STATIC) == 0)
        fields.put(f.getName(), f);
    _c = _c.getSuperclass();
  } while (_c != null);
  ret fields;
}