public async Task InvokesAddActivitySignupAsyncWithCorrectActivitySignup()
        {
            var message = new AddActivitySignupCommandAsync { ActivitySignup = new ActivitySignup() };
            var dataAccess = new Mock<IAllReadyDataAccess>();
            var sut = new AddActivitySignupCommandHandlerAsync(dataAccess.Object);
            await sut.Handle(message);

            dataAccess.Verify(x => x.AddActivitySignupAsync(message.ActivitySignup));
        }
        public async Task InvokesAddActivitySignupAsyncWithCorrectActivitySignup()
        {
            var message = new AddActivitySignupCommandAsync {
                ActivitySignup = new ActivitySignup()
            };
            var dataAccess = new Mock <IAllReadyDataAccess>();
            var sut        = new AddActivitySignupCommandHandlerAsync(dataAccess.Object);
            await sut.Handle(message);

            dataAccess.Verify(x => x.AddActivitySignupAsync(message.ActivitySignup));
        }