public void AddCreature(Creature creature)
 {
     if (Creatures.Count == 0)
     {
         ActiveCreature = creature;
     }
     Creatures.Add(creature);
 }
        public static void MySort <TSource, TKey>(this AdvisableCollection <TSource> observableCollection, Func <TSource, TKey> keySelector)
        {
            var a = observableCollection.OrderBy(keySelector).ToList();

            observableCollection.Clear();
            foreach (var b in a)
            {
                observableCollection.Add(b);
            }
        }