type,
              new InvocationHandler() {
                @Override
                public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                  if (!method.getDeclaringClass().equals(type)) {
                    return method.invoke(delegate, args);
                  }
                  checkState(started.getCount() == 1);
                  started.countDown();

    }
    checkArgument(
        !collection.isEmpty(), "collection is empty; use the other version of this method");
    Class<E> type = collection.iterator().next().getDeclaringClass();
    return makeComplementByHand(collection, type);
  }

  /**
   * Creates an {@code EnumSet} consisting of all enum values that are not in the specified