public UnitImpl produceUnit() {
hasProduced += 1;
treasury -= productionCost;
return unitProductionStrategy.produceUnit(ownedBy);
}
public void setProduction(String typeOfProduction) {
this.typeOfProduction = typeOfProduction;
unitProductionStrategy = new UnitFactory().createUnitStrategy(typeOfProduction);
productionCost = unitProductionStrategy.getCost();
}