code: protected void accomodateFrame (int frameIdx, int width, int height)
      {
          _bounds.width = width;
          _bounds.height = height;
      }
docs: Must adjust the bounds to accommodate the our new frame. This includes changing the width
  and height to reflect the size of the new frame and also updating the render origin (if
  necessary) and calling {@link Sprite#updateRenderOrigin} to reflect those changes in the
  sprite's bounds.
  
  @param frameIdx the index of our new frame.
  @param width the width of the new frame.
  @param height the height of the new frame.