/**
 * **NOTE**
 * Express adds `_locals`, see https://github.com/expressjs/express/blob/4.15.4/lib/response.js#L962.
 * But `options.data.root.context` is available next to `root._locals.context`, because
 * Express creates a `renderOptions` object, see https://github.com/expressjs/express/blob/4.15.4/lib/application.js#L554
 * and merges all locals to the root of the object. Very confusing, because the data is available in different layers.
 *
 * Express forwards the data like this to the hbs engine:
 * {
 *   post: {},             - res.render('view', databaseResponse)
 *   context: ['post'],    - from res.locals
 *   safeVersion: '1.x',   - from res.locals
 *   _locals: {
 *     context: ['post'],
 *     safeVersion: '1.x'
 *   }
 * }
 *
 * hbs forwards the data to any hbs helper like this
 * {
 *   data: {
 *     site: {},
 *     labs: {},
 *     config: {},
 *     root: {
 *       post: {},
 *       context: ['post'],
 *       locals: {...}
 *     }
 *  }
 *
 * `site`, `labs` and `config` are the templateOptions, search for `hbs.updateTemplateOptions` in the code base.
 *  Also see how the root object gets created, https://github.com/wycats/handlebars.js/blob/v4.0.6/lib/handlebars/runtime.js#L259
 */
declare function ghost_head(options: any): Promise<any>;
declare namespace ghost_head {
    var async: boolean;
}
export default ghost_head;