public void setup()
{
if (this.target != null)
{
removalSub = gameObject.AddComponent <IntObserver>();// dequeue index. usually 0.
removalSub.setupObserver(shiftByIndex);
target.effectRemoveSubscribe(removalSub);
additionSub = gameObject.AddComponent <GameObjectObserver>();
additionSub.setupObserver(effectAddToList);
target.effectAddSubscribe(additionSub);
death = gameObject.AddComponent <GameObjectObserver>();
death.setupObserver(targetDied);
target.deathSubscribe(death);
}
}