scope thisDollarOneFields.

static Map<Class, Field[]> #cache = newDangerousWeakHashMap();

static Field[] thisDollarOneFields(Class c) {
  synchronized(cache) {
    Field[] l = cache.get(c);
    if (l == null)
      cache.put(c, l = thisDollarOneFields_uncached(c));
    ret l;
  }
}

static Field[] thisDollarOneFields_uncached(Class c) {
  new L<Field> fields;
  do {
    for (Field f : c.getDeclaredFields())
      if (f.getName().startsWith("this$"))
        fields.add(makeAccessible(f));
    c = c.getSuperclass();
  } while (c != null);
  ret toArray(new Field[l(fields)], fields);
}

end scope

Began life as a copy of #1005599