title: UIPageViewControllerDataSource calls viewControllerAfterViewController twice the first time running
body: <p>I know this might be a duplicate but I tried other solutions found online and none of them seemed to solve my problem.</p>
  
  <p>I have a pageViewController that displays 4 UIViewControllers.
  At first scroll the pageController swipes to the third View controller but shows the second ViewController.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>_contentPageRestorationIDs = [[NSArray alloc]initWithObjects:@"PRPeripheralsOriantaionVC",@"PRSessionAnalysisDataVC", @"PRNavigationVC",@"PRVideoVC", nil];
  
  
  - (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController
  {
  return self.contentPageRestorationIDs.count;
  }
  
  - (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
  {
          NSString *vcRestorationID = viewController.restorationIdentifier;
      NSUInteger index = [self.contentPageRestorationIDs indexOfObject:vcRestorationID];
      NSLog(@"viewControllerBeforeViewController %@",vcRestorationID);
  
      if (index == 0)
      {
          return nil;
      }
  
      index--;
      return [self viewControllerAtIndex:index ];
  
  }
  
  - (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
  {
      NSString *vcRestorationID = viewController.restorationIdentifier;
  NSLog(@"viewControllerAfterViewController %@",vcRestorationID);
  
      NSUInteger index = [self.contentPageRestorationIDs indexOfObject:vcRestorationID];
      index ++;
      if (index == self.contentPageRestorationIDs.count )
      {
          return nil;
      }
  
      return [self viewControllerAtIndex:index ];
  
  }
  - (void)pageViewController:(UIPageViewController *)pageViewController willTransitionToViewControllers:(NSArray *)pendingViewControllers
  {
     NSLog(@"willTransitionToViewControllers %@ %lu",pendingViewControllers,(unsigned long)index);
  
  }
  
  -(void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray *)previousViewControllers transitionCompleted:(BOOL)completed
  {
  NSLog(@"didFinishAnimating %@",previousViewControllers);
  }
  </code></pre>