private void register(final @NotNull Locale locale, final @NotNull T translation) {
      if (this.translations.putIfAbsent(requireNonNull(locale, "locale"), requireNonNull(translation, "translation")) != null) {
        throw new IllegalArgumentException(String.format("Translation already exists: %s for %s", this.key, locale));
      }
    }
Returns a translation for a given key and locale, if any.

@param key the key
@param locale the locale
@return the translation, or {@code null} if none exists for this key
@since 4.20.0
api/src/main/java/net/kyori/adventure/translation/AbstractTranslationStore.java