public FPSSurfaceView addChild(@NonNull DisplayBase DisplayBase){
  DisplayBase.setUp(mFps);
  mDisplayList.add(DisplayBase);
  return this;
}

public FPSSurfaceView addChild ( @ NonNull DisplayBase DisplayBase ) { DisplayBase . setUp ( mFps ) ; mDisplayList . add ( DisplayBase ) ; return this ; }
adds a child to the top of the display list .
