b1-acharcode.dart

    /// رویدادهایی که به `counterBloc` واکنش نشان خواهند داد
    abstract class CounterEvent {}

    /// استیت افزایش را به بلاک اطلاعرسانی میکند
    class Increment extends CounterEvent {}

    /// A `CounterBloc` which handles converting `CounterEvent`s into `int`s.
    ///
    class CounterBloc extends Bloc<CounterEvent, int> {
      /// The initial state of the `CounterBloc` is 0.
      CounterBloc() : super(0) {
        /// When an `Increment` event is added,
        /// the current `state` of the bloc is accessed via the `state` property
        /// and a new state is emitted via `emit`.
        on<Increment>((event, emit) => emit(state + 1));
      }
    }