*   <li>Nulls test is not performed on method return values unless the method is a non-private
   *       static factory method whose return type is {@code cls} or {@code cls}'s subtype.
   * </ul>
   */
  public void testNulls(Class<?> cls) {
    try {
      doTestNulls(cls, Visibility.PACKAGE);
    } catch (Exception e) {
      throwIfUnchecked(e);
      throw new RuntimeException(e);

   *   <li>Nulls test is not performed on method return values unless the method is a non-private
   *       static factory method whose return type is {@code cls} or {@code cls}'s subtype.
   * </ul>
   */
  public void testNulls(Class<?> cls) {
    try {
      doTestNulls(cls, Visibility.PACKAGE);
    } catch (Exception e) {
      throwIfUnchecked(e);
      throw new RuntimeException(e);