private CityImprovementPivot(int productivityCost, int maintenanceCost, int purchasePrice, int sellValue, string name,
bool hasCitizenHappinessEffect, AdvancePivot advancePrerequisite, CityImprovementPivot improvementPrerequisite) :
base(productivityCost, advancePrerequisite, null, purchasePrice, name, hasCitizenHappinessEffect)
{
MaintenanceCost = maintenanceCost;
SellValue = sellValue;
ImprovementPrerequisite = improvementPrerequisite;
}
private WonderPivot(int productivityCost, AdvancePivot advancePrerequisite, AdvancePivot advanceObsolescence,
string name, bool hasCitizenHappinessEffect) :
base(productivityCost, advancePrerequisite, advanceObsolescence, -1, name, hasCitizenHappinessEffect)
{
}