maybeWhen<T>  method 
      
T
maybeWhen<T>({  
    
    
- T? guest()?,
- T? user()?,
- required T orElse(),
Implementation
T maybeWhen<T>({
  T? Function()? guest,
  T? Function()? user,
  required T Function() orElse,
}) =>
    {
      AccountKind.guest: guest,
      AccountKind.user: user,
    }[this]
        ?.call() ??
    orElse();