exchange method

Money exchange(Money amount)

Buys or sells currencyA

• If money of currencyA is being passed, it's being sold and currencyB is being returned
• If money of currencyB is being passed, currencyA is being bought returned

If none of above, Exception is thrown

Implementation

Money exchange(
  /// Amount to exchange
  Money amount,
) {
  if (amount.currency == currencyA) {
    return Money(_round(amount.amount * rateSell), currencyB);
  }

  if (amount.currency == currencyB) {
    return Money(_round(amount.amount / rateBuy), currencyA);
  }

  throw Exception('This currency is not supported by this constructor');
}