public static void AddShiftable(IUniverseShift shiftable) { if (shiftables == null) shiftables = new List<IUniverseShift>(); if (!shiftables.Contains(shiftable)) shiftables.Add(shiftable); }
public static void RemoveShiftable(IUniverseShift shiftable) { if (shiftables == null) shiftables = new List<IUniverseShift>(); shiftables.Remove(shiftable); }