code: public boolean isAvailable(String baseCode, String termCode){
          return isAvailable(Monetary.getCurrency(baseCode), Monetary.getCurrency(termCode));
      }
docs: Checks if an {@link javax.money.convert.ExchangeRate} between two {@link javax.money.CurrencyUnit} is
  available from this provider. This method should check, if a given rate
  is <i>currently</i> defined.
  
  @param baseCode the base currency code
  @param termCode the terminal/target currency code
  @return {@code true}, if such an {@link javax.money.convert.ExchangeRate} is currently
  defined.
  @throws javax.money.MonetaryException if one of the currency codes passed is not valid.