public async Task SendDirectNotificationAsync()

in src/Microsoft.Azure.NotificationHubs/NotificationHubClient.cs [2915:2975]
48 lines of code
5 McCabe index (conditional complexity)

        public async Task<NotificationOutcome> SendDirectNotificationAsync(Notification notification, IList<string> deviceHandles, CancellationToken cancellationToken)
        {
            if (notification == null)
            {
                throw new ArgumentNullException(nameof(notification));
            }

            if (deviceHandles==null)
            {
                throw new ArgumentNullException(nameof(deviceHandles));
            }

            if (deviceHandles.Count == 0)
            {
                throw new ArgumentException(message: $"{nameof(deviceHandles)} should contain at least one value", paramName: nameof(deviceHandles));
            }

            var requestUri = GetGenericRequestUriBuilder();
            requestUri.Path += "messages/$batch";
            AddToQuery(requestUri, "&direct");

            // Convert FcmNotification into GcmNotification
            notification = FcmToGcmNotificationTypeCast(notification);

            notification.ValidateAndPopulateHeaders();

            return await _retryPolicy.RunOperation(async (ct) =>
            {
                using (var request = CreateHttpRequest(HttpMethod.Post, requestUri.Uri, out var trackingId))
                {
                    foreach (var item in notification.Headers)
                    {
                        request.Headers.Add(item.Key, item.Value);
                    }

                    var content = new MultipartContent("mixed", "nh-batch-multipart-boundary");

                    ParseContentType(notification.ContentType, out var mediaType, out var encoding);

                    var notificationContent = new StringContent(notification.Body, encoding, mediaType);
                    notificationContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("inline") { Name = "notification" };
                    content.Add(notificationContent);

                    var devicesContent = new StringContent(JsonConvert.SerializeObject(deviceHandles), Encoding.UTF8, "application/json");
                    devicesContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("inline") { Name = "devices" };
                    content.Add(devicesContent);

                    request.Content = content;

                    using (var response = await SendRequestAsync(request, trackingId, HttpStatusCode.Created, ct).ConfigureAwait(false))
                    {
                        return new NotificationOutcome()
                        {
                            State = NotificationOutcomeState.Enqueued,
                            TrackingId = trackingId,
                            NotificationId = GetNotificationIdFromResponse(response)
                        };
                    }
                }
            }, cancellationToken);
        }