@Override
 public void dispose() {
   if (motionState != null) motionState.release();
   motionState = null;
   if (collisionShape != null) collisionShape.release();
   collisionShape = null;
   super.dispose();
 }
 @Override
 public void dispose() {
   if (swigCPtr != 0) removeInstance(this);
   if (gdxBridge != null) gdxBridge.dispose();
   gdxBridge = null;
   if (collisionShape != null) collisionShape.release();
   collisionShape = null;
   super.dispose();
 }
 protected void refCollisionShape(btCollisionShape shape) {
   if (collisionShape == shape) return;
   if (collisionShape != null) collisionShape.release();
   collisionShape = shape;
   collisionShape.obtain();
 }