code: function parseClipRect(cr) {
      const params = (cr || '').match(REGEXP_CLIP_RECT);
      if (params && (params.length === 5)) {
          return {
              top: parseInt(params[1]),
              left: parseInt(params[2]),
              width: parseInt(params[3]),
              height: parseInt(params[4])
          };
      }
      return null;
  }
docs: /* Functions to parse options