### Question:
LocalizedString extends Base { public LocalizedString slugified() { return mapValue((locale, value) -> slugify(value)); } @JsonCreator private  LocalizedString(final Map<Locale, String> translations); @JsonIgnore static LocalizedString of(); static LocalizedString empty(); @JsonIgnore static LocalizedString of(final Locale locale, final String value); @JsonIgnore static LocalizedString of(final Locale locale1, final String value1, final Locale locale2, final String value2); @JsonIgnore static LocalizedString of(final Map<Locale, String> translations); @JsonIgnore static LocalizedString ofStringToStringMap(final Map<String, String> translations); LocalizedString plus(final Locale locale, final String value); @Nonnull Optional<String> find(final Locale locale); @Nullable String get(final Locale locale); @Nullable String get(final String languageTag); @Nonnull Optional<String> find(final Iterable<Locale> locales); @Nullable String get(final Iterable<Locale> locales); @Nullable String getTranslation(final Iterable<Locale> locales); LocalizedString mapValue(final BiFunction<Locale, String, String> function); Stream<LocalizedStringEntry> stream(); static Collector<LocalizedStringEntry, ?, LocalizedString> streamCollector(); LocalizedString slugified(); LocalizedString slugifiedUnique(); @JsonIgnore @Nonnull Set<Locale> getLocales(); @Override String toString(); static TypeReference<LocalizedString> typeReference(); static LocalizedString ofEnglish(final String translationForEnglish);  }### Answer:
@Test public void slugified() { final LocalizedString ls = LocalizedString.of(Locale.GERMAN, "Hundefutter", Locale.ENGLISH, "dog food"); assertThat(ls.slugified()) .isEqualTo(LocalizedString.of(Locale.GERMAN, "hundefutter", Locale.ENGLISH, "dog-food")); }