public ExchangeRate(decimal rate, ExchangeSymbol exchangeSymbol, DateTime date, CultureInfo cultureInfo)
{
Rate = rate;
Date = date;
_cultureInfo = cultureInfo;
Symbol = exchangeSymbol ?? throw new ArgumentNullException(nameof(exchangeSymbol));
}
public ExchangeRate(decimal rate, string fromSymbol, string toSymbol, DateTime date, CultureInfo cultureInfo)
{
Rate = rate;
Date = date;
_cultureInfo = cultureInfo;
Symbol = new ExchangeSymbol(fromSymbol, toSymbol);
}