SlitInVertical constructor
      
      SlitInVertical({ 
    
    
- Key? key,
 - required Widget child,
 - AnimationPreferences preferences = const AnimationPreferences(duration: Duration(milliseconds: 750)),
 
Implementation
SlitInVertical({
  Key? key,
  required Widget child,
  AnimationPreferences preferences =
      const AnimationPreferences(duration: Duration(milliseconds: 750)),
}) : super(
          key: key,
          child: child,
          definition: SlitInVerticalAnimation(preferences: preferences));