public void clear(ArrayList<Sprite> mSprites) {
   final Engine.EngineLock engineLock = engine.getEngineLock();
   engineLock.lock();
   for (Sprite s : mSprites) detach(s);
   engineLock.unlock();
 }
 public void clear(Sprite s) {
   final Engine.EngineLock engineLock = engine.getEngineLock();
   engineLock.lock();
   detach(s);
   engineLock.unlock();
 }
 public void clear(Sprite[][] mSprites) {
   final Engine.EngineLock engineLock = engine.getEngineLock();
   engineLock.lock();
   for (Sprite[] ss : mSprites) for (Sprite s : ss) detach(s);
   engineLock.unlock();
 }
 public void clear(Sprite s, Sprite fromSprite) {
   final Engine.EngineLock engineLock = engine.getEngineLock();
   engineLock.lock();
   detach(s, fromSprite);
   engineLock.unlock();
 }