static {
      ImmutableMap.Builder<String, Method> builder = ImmutableMap.builder();
      for (Method method : TypeVariableImpl.class.getMethods()) {
        if (method.getDeclaringClass().equals(TypeVariableImpl.class)) {
          try {
            method.setAccessible(true);
          } catch (AccessControlException e) {

    }
    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