public async Task SavePreferenceAsync(PreferenceDto preference)
        {
            var previousPreference = await _preferenceRepository.GetPreferenceAsync(preference.EmployeeId, preference.DrinkId);

            await _preferenceRepository.SavePreferenceAsync(
                Preference.Create(
                    preference.EmployeeId,
                    preference.DrinkId,
                    new DrinkPreference(
                        preference.Amounts.Select(a => new IngredientAmount(a.DrinkIngredientId, a.Amount)),
                        preference.Mug
                        ),
                    preferenceId: previousPreference?.PreferenceId ?? 0));
        }