public void Update(ICurrentUsageAnswer answer)
        {
            if (IsGasComparison())
            {
                GasUsageType.SetAnswer(answer.GasUsageType);
                GasSimpleEstimate.SetAnswer(answer.GasUsageSimpleEstimator);

                GasHouseType.SetAnswer(answer.HouseType);
                GasNumberOfBedrooms.SetAnswer(answer.NumberOfBedrooms);
                GasMainCookingSource.SetAnswer(answer.MainCookingSource);
                GasCookingFrequency.SetAnswer(answer.CookingFrequency);
                GasCentralHeating.SetAnswer(answer.CentralHeating);
                GasNumberOfOccupants.SetAnswer(answer.NumberOfOccupants);
                GasInsulation.SetAnswer(answer.Insulation);
                GasEnergyUsage.SetAnswer(answer.EnergyUsage);

                GasCurrentSpend.SetAnswer(answer.GasCurrentSpend);
                GasCurrentUsageAsKwh.SetAnswer(answer.GasCurrentUsageAsKwh);
            }

            if (IsElecComparison())
            {
                ElecUsageType.SetAnswer(answer.ElectricityUsageType);
                ElecSimpleEstimate.SetAnswer(answer.ElectricityUsageSimpleEstimator);

                ElectricityHouseType.SetAnswer(answer.HouseType);
                ElectricityNumberOfBedrooms.SetAnswer(answer.NumberOfBedrooms);
                ElectricityMainCookingSource.SetAnswer(answer.MainCookingSource);
                ElectricityCookingFrequency.SetAnswer(answer.CookingFrequency);
                ElectricityCentralHeating.SetAnswer(answer.CentralHeating);
                ElectricityNumberOfOccupants.SetAnswer(answer.NumberOfOccupants);
                ElectricityInsulation.SetAnswer(answer.Insulation);
                ElectricityEnergyUsage.SetAnswer(answer.EnergyUsage);

                ElectricityCurrentSpend.SetAnswer(answer.ElectricityCurrentSpend);
                ElectricityCurrentUsageAsKwh.SetAnswer(answer.ElectricityCurrentUsageAsKwh);

                if (IsEconomy7(answer))
                {
                    NightUsagePercentage.SetAnswer(new Percentage(answer.NightPercentageUsage));
                }
            }
        }
 private static bool IsEconomy7(ICurrentUsageAnswer answer) => !string.IsNullOrEmpty(answer.NightPercentageUsage);