LocalizableObject implements Localizable { public void enableLanguage(Language language) { if (language == null) throw new IllegalArgumentException("Language must not be null"); if (!languages.contains(language)) { languages.add(language); if (languages.size() == 1) { originalLanguage = language; currentLanguage = language; } } } LocalizableObject();  LocalizableObject(Language defaultLanguage); void addLocalizationListener(LocalizationListener listener); void removeLocalizationListener(LocalizationListener listener); void enableLanguage(Language language); void disableLanguage(Language language); Language switchTo(Language language); Language switchTo(Language language, boolean force); Language getLanguage(); void setLanguageResolution(LanguageResolution behavior); LanguageResolution getLanguageResolution(); void setDefaultLanguage(Language language); Language getDefaultLanguage(); Language getOriginalLanguage(); void setOriginalLanguage(Language language); boolean supportsLanguage(Language language); Set<Language> languages(); int compareTo(Localizable o, Language l); String toString(); String toString(Language language); String toString(Language language, boolean force);  }
@Test public void testEnableLanguage() { content.enableLanguage(italian); assertTrue(content.supportsLanguage(italian)); }