whenOrNull<TResult extends Object?> method Null safety

TResult? whenOrNull<TResult extends Object?>(
  1. {TResult? initial(
      )?,
    1. TResult? apps(
      1. List<String> apps
      )?,
    2. TResult? archive(
        )?,
      1. TResult? data(
        1. List<String> data
        )?,
      2. TResult? processing(
        1. int progress
        )?,
      3. TResult? completed(
          )?,
        1. TResult? errored(
          1. Object error,
          2. StackTrace stackTrace
          )?}
        )
        inherited

        Implementation

        @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  TResult? Function()? initial,
  TResult? Function(List<String> apps)? apps,
  TResult? Function()? archive,
  TResult? Function(List<String> data)? data,
  TResult? Function(int progress)? processing,
  TResult? Function()? completed,
  TResult? Function(Object error, StackTrace stackTrace)? errored,
}) =>
    throw _privateConstructorUsedError;