public override void Write(byte[] buffer, int offset, int count) {
byte[] bytesToSend = null;
if (offset != 0 || count != buffer.Length) {
bytesToSend = new byte[count];
Array.Copy(buffer, offset, bytesToSend, 0, count);
} else {
bytesToSend = buffer;
}
_length = _blobService.BlobWriteAsync(_blob.Id, bytesToSend, _position).GetAwaiter().GetResult();
_position += count;
}