load() {
		if (this.menu == null)
			this.menu = session.getLocalData('menu');

		if (!L.isObject(this.menu)) {
			this.menu = request.get(L.url('admin/menu')).then(L.bind((menu) => {
				this.menu = scrubMenu(menu.json());
				session.setLocalData('menu', this.menu);

				return this.menu;
			}, this));
		}

		return Promise.resolve(this.menu);
	}
Load and cache current menu tree.

@returns {Promise<LuCI.ui.menu.MenuNode>}
Returns a promise resolving to the root element of the menu tree.