assertEquals("", defaultConverter.reverse().convert(123));
      assertNull(defaultConverter.convert(null));
      assertNull(defaultConverter.reverse().convert(null));
    }
  }

  public void testConverterDefaultValue() {
    new ConverterDefaultValueChecker().check();
  }

  private static class VisibilityMethods {

    private void privateMethod() {}

    void packagePrivateMethod() {}