Finish background task in iOS

Finish background task

bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:
           ^{
                 [[UIApplication sharedApplication] endBackgroundTask:bgTask];
            }];

// Now call methods doing network activity
// ...
// WHEN I KNOW THE LAST ACTION HAS COMPLETED USE THIS BLOCK OF CODE

if (bgTask != UIBackgroundTaskInvalid)
{
      [[UIApplication sharedApplication] endBackgroundTask:bgTask];
      bgTask = UIBackgroundTaskInvalid;
}