Scale9Bitmap(BitmapData bitmapData, Rectangle<num> grid)

Source 

Scale9Bitmap(BitmapData bitmapData, Rectangle<num> grid) : super(bitmapData) {
  _grid = grid;
  _width = ensureNum(bitmapData.width);
  _height = ensureNum(bitmapData.height);
  _updateRenderTextureQuads();
}