public void SetBuffer(byte[] buffer, int offset, int count)
{
Debug.Assert(!_shouldCloseOutput, "'m_ShouldCloseOutput' MUST be 'false' at this point.");
Debug.Assert(buffer == null || _bufferList == null, "Either 'm_Buffer' or 'm_BufferList' MUST be NULL.");
_buffer = buffer;
_offset = offset;
_count = count;
}