public override void DidFinishDownloading (NSUrlSession session, NSUrlSessionDownloadTask downloadTask, NSUrl location)
		{
			CopyDownloadedImage (location);

			var message = new DownloadFinishedMessage () {
				FilePath = targetFileName,
				Url = downloadTask.OriginalRequest.Url.AbsoluteString
			};

			MessagingCenter.Send<DownloadFinishedMessage> (message, "DownloadFinishedMessage");

		}
		public  override StartCommandResult OnStartCommand (Intent intent, StartCommandFlags flags, int startId)
		{
			var url = intent.GetStringExtra ("url");

            Task.Run (() => {
				var imageHelper = new ImageHelper ();
				imageHelper.DownloadImageAsync (url)
                        .ContinueWith (filePath => {
					                        var message = new DownloadFinishedMessage {
						                        FilePath = filePath.Result
					                        };
					                        MessagingCenter.Send (message, "DownloadFinishedMessage");
				                        });
			});

			return StartCommandResult.Sticky;
		}