st         if (centerRegion.regionToNorth != nil && centerRegion.regionToNorth.regionToWest != nil)         {             self.region = centerRegion.regionToNorth.regionToWest;             [self reloadRegion];             self.regionToNorthwestScreenshot = [self.collectionView snapshotViewAfterScreenUpdates:YES];         }         else         {             self.regionToNorthwestScreenshot = [[UIView alloc] init];             self.regionToNorthwestScreenshot.backgroundColor = [UIColor darkGrayColor];         }         [self.view.superview addSubview:self.regionToNorth