Converter<String, Integer> defaultConverter =
          (Converter<String, Integer>) getDefaultParameterValue(0);
      assertEquals(Integer.valueOf(0), defaultConverter.convert("anything"));
      assertThat(defaultConverter.reverse().convert(123)).isEqualTo("");
      assertThat(defaultConverter.convert(null)).isNull();
      assertThat(defaultConverter.reverse().convert(null)).isNull();
    }
  }