static getBrushBBox(points) {
    const [x1, y1, x2, y2] = Geometry.getPointsBBox(points);

    return { x: x1, y: y1, width: x2 - x1, height: y2 - y1 };
  }
Calculate BBox of Brush region (a set of points)
@param {Points} points
@return {BBox[]}