internal int ReadInt32(int numBits)
        {
            if (numBits <= 0)
                return 0;
            int ret = 0;
            while (true)
            {
                if (ReadPos >= _numBits)
                {
                    return ret;
                }

                int pos7 = (ReadPos & 7);
                int bitsLeftInByte = 8 - pos7;

                int subNum = bitsLeftInByte;
                if (bitsLeftInByte >= numBits)
                    subNum = numBits;

                var lShift = (byte) (1 << subNum);

                int v10 = _buffer[ReadPos >> 3] >> (ReadPos & 7);
                numBits -= subNum;

                ret |= ((lShift - 1) & v10) << numBits;
                _readPos = ReadPos + subNum;

                if (numBits == 0)
                    return ret;
            }
        }