docs: public static CurrencyUnit of(Locale locale) {
          MoneyUtils.checkNotNull(locale, "Locale must not be null");
          CurrencyUnit currency = currenciesByCountry.get(locale.getCountry());
          if (currency == null) {
              throw new IllegalCurrencyException("No currency found for locale '" + locale + '\'');
          }
          return currency;
      }