How to use the ionicons/icons.close.md function in ionicons

export function appInitialize(config?: IonicConfig) {
  const win: IonicWindow = window as any;
  const Ionic = (win.Ionic = win.Ionic || {});

  Ionic.config = config;

  applyPolyfills().then(() => defineCustomElements(win));

  addIcons({
    'ios-close': close.ios,
    'md-close': close.md,
    'ios-reorder': reorder.ios,
    'md-reorder': reorder.md,
    'ios-menu': menu.ios,
    'md-menu': menu.md,
    'ios-arrow-forward': arrowForward.ios,
    'md-arrow-forward': arrowForward.md,
    'ios-arrow-back': arrowBack.ios,
    'md-arrow-back': arrowBack.md,
    'ios-arrow-down': arrowDown.ios,
    'md-arrow-down': arrowDown.md,
    'ios-search': search.ios,
    'md-search': search.md,
    'ios-close-circle': closeCircle.ios,
    'md-close-circle': closeCircle.md,
  });
}