public async Task Handle_バリデーションエラーがない場合は何もおこらず完了する()
    {
        var executed = false;
        var behavior = new DataAnnotationValidationBehavior <TestBehaviorRequest, TestBehaviorResponse>();
        await behavior.Handle(new TestBehaviorRequest()
        {
            Value = "A"
        }, new CancellationToken(), () =>
        {
            executed = true;
            return(Task.FromResult(new TestBehaviorResponse()));
        });

        executed.Should().BeTrue();
    }
    public async Task Handle_バリデーションエラーがある場合は例外が発生して処理が継続されない()
    {
        var executed = false;
        var behavior = new DataAnnotationValidationBehavior <TestBehaviorRequest, TestBehaviorResponse>();
        var act      = () => behavior.Handle(new TestBehaviorRequest()
        {
            Value = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        }, new CancellationToken(), () =>
        {
            executed = true;
            return(Task.FromResult(new TestBehaviorResponse()));
        });

        await act.Should().ThrowAsync <ValidationException>();

        executed.Should().BeFalse();
    }