public function add_panel( $args ) {
		global $wp_customize;

		if ( ! isset( $args['type'] ) || ! array_key_exists( $args['type'], $this->panel_types ) ) {
			$args['type'] = 'default';
		}
		$panel_classname = $this->panel_types[ $args['type'] ];

		$wp_customize->add_panel( new $panel_classname( $wp_customize, $args['id'], $args ) );
	}