addStyleClass(t, s = "") {
    this.classes.has(t) || this.classes.set(t, { id: t, styles: [], textStyles: [] });
    const n = this.classes.get(t);
    s != null && s.split(Ue).forEach((o) => {
      const c = o.replace(/([^;]*);/, "$1").trim();
      if (RegExp(Yt).exec(o)) {
        const d = c.replace(Ft, Me).replace(Yt, Ft);
        n.textStyles.push(d);
      }
      n.styles.push(c);
    });
  }
Called when the parser comes across a (style) class definition
@example classDef my-style fill:#f96;

@param {string} id - the id of this (style) class
@param  {string | null} styleAttributes - the string with 1 or more style attributes (each separated by a comma)