Function<String, String> japaneseToSpanish =
        Functions.compose(numberToSpanish, japaneseToInteger);
  }

  private static class HashCodeFunction implements Function<@Nullable Object, Integer> {
    @Override
    public Integer apply(@Nullable Object o) {
      return (o == null) ? 0 : o.hashCode();
    }
  }

    Function<String, String> japaneseToSpanish =
        Functions.compose(numberToSpanish, japaneseToInteger);
  }

  private static class HashCodeFunction implements Function<@Nullable Object, Integer> {
    @Override
    public Integer apply(@Nullable Object o) {
      return (o == null) ? 0 : o.hashCode();
    }
  }