import { HeaderItem } from './types.js';
/**
 * Creates a flexible, empty "spacer" header item.
 *
 * The spacer renders nothing but grows (`fill: 'grow'`) to fill the available width, separating the
 * leading group of items (e.g. the title) from the trailing group (action buttons). It is also the
 * anchor that `{ type: 'auto' }` items are placed after.
 */
export declare const createHeaderSpacerItem: (id: string) => HeaderItem;