How to use the @material/menu-surface.MDCMenuSurfaceFoundation.cssClasses function in @material/menu-surface

componentDidMount() {
    if (this.root.ref) {
      const anchor = closest(
        this.root.ref,
        `.${MDCMenuSurfaceFoundation.cssClasses.ANCHOR}`
      );
      anchor && (this.anchorElement = anchor);
    }
    // this has to be run AFTER we try to get our anchor
    super.componentDidMount();
  }

useEffect(() => {
    const el = rootEl.ref;

    if (el) {
      const anchor = closest(
        el,
        `.${MDCMenuSurfaceFoundation.cssClasses.ANCHOR}`
      );
      anchor && (anchorElementRef.current = anchor);
    }
  }, [rootEl.ref]);