Converter<Long, String> reverseConverter = STR_TO_LONG.reverse();

    assertThat(reverseConverter.convert(LONG_VAL)).isEqualTo(STR_VAL);
    assertEquals(LONG_VAL, reverseConverter.reverse().convert(STR_VAL));

    Iterable<String> convertedValues = reverseConverter.convertAll(LONGS);
    assertEquals(STRINGS, ImmutableList.copyOf(convertedValues));

    assertThat(reverseConverter.reverse()).isSameInstanceAs(STR_TO_LONG);