code: private Shape decodeMarkBorder(int width, int height) {
          double left = width / 2.0 - 4;
          double top  = height / 2.0 - 4;
  
          path.reset();
          path.moveTo(left + 0, top + 0);
          path.lineTo(left + 8, top);
          path.lineTo(left + 4, top + 6);
          path.closePath();
  
          return path;
      }
docs: Create the mark border shape.
  
  @param  width  the width.
  @param  height the height.
  
  @return the shape of the mark border.