protected BanknoteHandler(BanknoteHandler nextHandler) { _nextHandler = nextHandler; }
protected CurrencyHandlerBase(BanknoteHandler nextHandler) : base(nextHandler) { }
protected BanknoteHandler(BanknoteHandler nextHandler) { _nextHandler = nextHandler; }
protected CurrencyHandlerBase(BanknoteHandler nextHandler) : base(nextHandler) { }