isBeingDismissed is not work

        viewController.isBeingPresented == NO;
        [rootVC presentViewController:viewController animated:NO completion:^{
            viewController.isBeingPresented == NO;
            viewController.isBeingDismissed == NO;
            [viewController dismissViewControllerAnimated:NO completion:^{
                viewController.isBeingDismissed == NO;
            }];
            viewController.isBeingDismissed == NO;    // is not work
        }];
        viewController.isBeingPresented == YES;     // is work
        
        
        
        viewController.isBeingPresented == NO;
        [rootVC presentViewController:viewController animated:NO completion:^{
            viewController.isBeingPresented == NO;
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                viewController.isBeingDismissed == NO;
                [viewController dismissViewControllerAnimated:NO completion:^{
                    viewController.isBeingDismissed == NO;
                }];
                viewController.isBeingDismissed == YES;    // is work
            });
        }];
        viewController.isBeingPresented == YES;     // is work