public void Remove(IViewSprite oldSprite)
 {
   _mutex.WaitOne();
   _spriteContainer.Remove(oldSprite);
   _mutex.ReleaseMutex();
 }
 public void Add(IViewSprite newSprite)
 {
   _mutex.WaitOne();
   _spriteContainer.Add(newSprite);
   _mutex.ReleaseMutex();
 }