public async Task Then_If_Has_Id_Is_Valid(
            CreateReservationCommandValidator validator)
        {
            var command = new CreateReservationCommand
            {
                Id = Guid.NewGuid()
            };

            var result = await validator.ValidateAsync(command);

            result.IsValid().Should().BeTrue();
        }
        public async Task Then_If_Has_No_Id_Is_Invalid(
            CreateReservationCommandValidator validator)
        {
            var command = new CreateReservationCommand();

            var result = await validator.ValidateAsync(command);

            result.IsValid().Should().BeFalse();
            result.ValidationDictionary.Count.Should().Be(1);
            result.ValidationDictionary
            .Should().ContainKey(nameof(CreateReservationCommand.Id))
            .WhichValue.Should().Be($"{nameof(CreateReservationCommand.Id)} has not been supplied");
        }