public ExchangeRate(string fromCurrency, string toCurrency, decimal exchangeRateValue)
{
CurrencyPair = new CurrencyPair(fromCurrency, toCurrency);
Rate = exchangeRateValue;
}
public ExchangeRate(CurrencyPair currencyPair, decimal exchangeRateValue)
{
CurrencyPair = currencyPair;
Rate = exchangeRateValue;
}