protected virtual void Subscribe(AUnitElementData elementData) {
_subscriptions.Add(elementData, new List<IDisposable>());
IList<IDisposable> anElementsSubscriptions = _subscriptions[elementData];
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, float>(ed => ed.CurrentHitPoints, ElementCurrentHitPtsPropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, float>(ed => ed.MaxHitPoints, ElementMaxHitPtsPropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, CombatStrength>(ed => ed.DefensiveStrength, ElementDefensiveStrengthPropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, CombatStrength>(ed => ed.OffensiveStrength, ElementOffensiveStrengthPropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, RangeDistance>(ed => ed.WeaponsRange, ElementWeaponsRangePropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, RangeDistance>(ed => ed.SensorRange, ElementSensorRangePropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, float>(ed => ed.Science, ElementSciencePropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, float>(ed => ed.Culture, ElementCulturePropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, float>(ed => ed.Income, ElementIncomePropChangedHandler));
anElementsSubscriptions.Add(elementData.SubscribeToPropertyChanged<AUnitElementData, float>(ed => ed.Expense, ElementExpensePropChangedHandler));
}
