setCssClass(i, a) {
    i.split(",").forEach((u) => {
      let l = u;
      /\d/.exec(u[0]) && (l = pe + l);
      const r = this.classes.get(l);
      r && (r.cssClasses += " " + a);
    });
  }
Called by parser when assigning cssClass to a class

@param ids - Comma separated list of ids
@param className - Class to add