public sealed class SimpleTask : IBackgroundTask

     {

         public void Run(IBackgroundTaskInstance taskInstance)

         {

             // TODO

         }

     }

     public sealed class SimpleAsyncTask : IBackgroundTask

     {

         public async void Run(IBackgroundTaskInstance taskInstance)

         {

             BackgroundTaskDeferral deferral = taskInstance.GetDeferral();

             // TODO

             deferral.Complete();

         }

     }