BACnet.Core.App.Transactions.ClientTransaction._inWindow C# (CSharp) Метод

        private int _inWindow(byte sequenceNumber)
        {
            int full = _windowStart - (_windowStart % 256) + sequenceNumber;
            if (full >= _windowStart && full < _windowStart + _windowSize)
                return full;
            else
                return -1;
        }