text: export default function Anchor(node, {classForward = () => {}}) {
    let classList = [];
  
    function addClass(className) {
      const idx = classList.indexOf(className);
      if (idx === -1) {
        node.classList.add(className);
        classList.push(className);
        if (classForward) {
          classForward(classList);
        }
      }
    }
  
    function removeClass(className) {
      const idx = classList.indexOf(className);
      if (idx !== -1) {
        node.classList.remove(className);
        classList.splice(idx, 1);
        if (classForward) {
          classForward(classList);
        }
      }
    }
  
    addClass('mdc-menu-surface--anchor');
  
    return {
      destroy() {
        removeClass('mdc-menu-surface--anchor');
      }
    }
  }