public function list_( $args, $assoc_args ) {

		$locations     = get_registered_nav_menus();
		$location_objs = [];
		foreach ( $locations as $location => $description ) {
			$location_obj              = new stdClass();
			$location_obj->location    = $location;
			$location_obj->description = $description;
			$location_objs[]           = $location_obj;
		}

		$formatter = new Formatter( $assoc_args, [ 'location', 'description' ] );

		if ( 'ids' === $formatter->format ) {
			$ids = array_map(
				function( $o ) {
					return $o->location;
				},
				$location_objs
			);
			$formatter->display_items( $ids );
		} else {
			$formatter->display_items( $location_objs );
		}
	}