public PopStateMessage(GameState curState)
{
if(curState == null)
throw new NullReferenceException("Cannot Make PopStateMessage without valid current state");
this.curState = curState;
}
public PushNewStateMessage(GameState newState)
{
//make sure the state is valid
if (newState == null)
throw new NullReferenceException("Cannot Make PushNewStateMessage without valid target state");
targetState = newState;
}