Akka.Streams.Implementation.IO.FileSubscriber.Receive C# (CSharp) Method

        protected override bool Receive(object message)
        {
            return message.Match()
                .With<OnNext>(next =>
                {
                    try
                    {
                        var byteString = (ByteString) next.Element;
                        var bytes = (byteString.AsByteBuffer()).Array();
                         _chan.Write(bytes, 0, bytes.Length);
                        _bytesWritten += bytes.Length;
                    }
                    catch (Exception ex)
                    {
                        _completionPromise.TrySetResult(new IOResult(_bytesWritten, Result.Failure<NotUsed>(ex)));
                        Cancel();
                    }
                })
                .With<OnError>(error =>
                {
                    _log.Error(error.Cause, $"Tearing down FileSink({_f.FullName}) due to upstream error");
                    _completionPromise.TrySetResult(new IOResult(_bytesWritten, Result.Failure<NotUsed>(error.Cause)));
                    Context.Stop(Self);
                })
                .With<OnComplete>(() =>
                {
                    try
                    {
                        _chan.Flush(true);
                    }
                    catch (Exception ex)
                    {
                        _completionPromise.TrySetResult(new IOResult(_bytesWritten, Result.Failure<NotUsed>(ex)));
                    } 
                    Context.Stop(Self);
                })
                .WasHandled;
        }