code: public static MonetaryContext from(MonetaryContext monetaryContext, Class<? extends MonetaryAmount> amountClass) {
          return MonetaryContextBuilder.of(amountClass).importContext(monetaryContext).build();
      }
docs: Creates a new {@link }MonetaryContext).
  
  @param monetaryContext the base context, not null.
  @param amountClass     the target amount class.
  @return a new corresponding MonetaryContext instance.