code: public static MonetaryRounding getRounding(String roundingName, String... providers) {
          return Optional.ofNullable(monetaryRoundingsSingletonSpi()).orElseThrow(
                  () -> new MonetaryException("No MonetaryRoundingsSpi loaded, query functionality is not available."))
                  .getRounding(roundingName, providers);
      }
docs: Access an {@link MonetaryOperator} for custom rounding
  {@link MonetaryAmount} instances.
  
  @param roundingName The rounding identifier.
  @param providers    the providers and ordering to be used. By default providers and ordering as defined in
  #getDefaultProviders is used.
  @return the corresponding {@link MonetaryOperator} implementing the
  rounding, never {@code null}.
  @throws IllegalArgumentException if no such rounding is registered using a
  {@link javax.money.spi.RoundingProviderSpi} instance.