public FPSSurfaceView addChildAt(int location,@NonNull DisplayBase DisplayBase){
  DisplayBase.setUp(mFps);
  mDisplayList.add(location,DisplayBase);
  return this;
}

public FPSSurfaceView addChildAt ( int location , @ NonNull DisplayBase DisplayBase ) { DisplayBase . setUp ( mFps ) ; mDisplayList . add ( location , DisplayBase ) ; return this ; }
adds a child to the display list at the specified index , bumping children at equal or greater indexes up one , and setting its parent to this container
