'menu_item_parent', 'id' => 'db_id' );
	/**
	 * Starts the list before the elements are added.
	 *
	 * @see Walker::start_lvl()
	 *
	 * @since 3.0.0
	 *
	 * @param string $output Passed by reference. Used to append additional content.
	 * @param int    $depth  Depth of menu item. Used for padding.
	 * @param array  $args   An array of arguments. @see wp_nav_menu()
	 */
	public function start_lvl( &$output, $depth = 0, $args = array() ) {
		$indent = str_repeat("\t", $depth);
		$output .= "\n$indent
\n";
	}
	/**
	 * Start the element output.
	 *
	 * @see Walker::start_el()
	 *
	 * @since 3.0.0
	 *
	 * @param string $output Passed by reference. Used to append additional content.
	 * @param object $item   Menu item data object.
	 * @param int    $depth  Depth of menu item. Used for padding.
	 * @param array  $args   An array of arguments. @see wp_nav_menu()
	 * @param int    $id     Current item ID.
	 */
	public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
		$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
		$classes = empty( $item->classes ) ? array() : (array) $item->classes;
		$classes[] = 'menu-item-' . $item->ID;
		/**
		 * Filter the CSS class(es) applied to a menu item's .
		 *
		 * @since 3.0.0
		 *
		 * @see wp_nav_menu()
		 *
		 * @param array  $classes The CSS classes that are applied to the menu item's .
		 * @param object $item    The current menu item.
		 * @param array  $args    An array of wp_nav_menu() arguments.
		 */
		$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
		$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
		/**
		 * Filter the ID applied to a menu item's .
		 *
		 * @since 3.0.1
		 *
		 * @see wp_nav_menu()
		 *
		 * @param string $menu_id The ID that is applied to the menu item's .
		 * @param object $item    The current menu item.
		 * @param array  $args    An array of wp_nav_menu() arguments.
		 */
		$id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
		$id = $id ? ' id="' . esc_attr( $id ) . '"' : '';
		$output .= $indent . '';
		$atts = array();
		$atts['title']  = ! empty( $item->attr_title ) ? $item->attr_title : '';
		$atts['target'] = ! empty( $item->target )     ? $item->target     : '';
		$atts['rel']    = ! empty( $item->xfn )        ? $item->xfn        : '';
		$atts['href']   = ! empty( $item->url )        ? $item->url        : '';
		/**
		 * Filter the HTML attributes applied to a menu item's .
		 *
		 * @since 3.6.0
		 *
		 * @see wp_nav_menu()
		 *
		 * @param array $atts {
		 *     The HTML attributes applied to the menu item's , empty strings are ignored.
		 *
		 *     @type string $title  Title attribute.
		 *     @type string $target Target attribute.
		 *     @type string $rel    The rel attribute.
		 *     @type string $href   The href attribute.
		 * }
		 * @param object $item The current menu item.
		 * @param array  $args An array of wp_nav_menu() arguments.
		 */
		$atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );
		$attributes = '';
		foreach ( $atts as $attr => $value ) {
			if ( ! empty( $value ) ) {
				$value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
				$attributes .= ' ' . $attr . '="' . $value . '"';
			}
		}
		$item_output = $args->before;
		$item_output .= '';
		/** This filter is documented in wp-includes/post-template.php */
		$item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
		$item_output .= '';
		$item_output .= $args->after;
		/**
		 * Filter a menu item's starting output.
		 *
		 * The menu item's starting output only includes $args->before, the opening ,
		 * the menu item's title, the closing , and $args->after. Currently, there is
		 * no filter for modifying the opening and closing  for a menu item.
		 *
		 * @since 3.0.0
		 *
		 * @see wp_nav_menu()
		 *
		 * @param string $item_output The menu item's starting HTML output.
		 * @param object $item        Menu item data object.
		 * @param int    $depth       Depth of menu item. Used for padding.
		 * @param array  $args        An array of wp_nav_menu() arguments.
		 */
		$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
	}
	/**
	 * Ends the element output, if needed.
	 *
	 * @see Walker::end_el()
	 *
	 * @since 3.0.0
	 *
	 * @param string $output Passed by reference. Used to append additional content.
	 * @param object $item   Page data object. Not used.
	 * @param int    $depth  Depth of page. Not Used.
	 * @param array  $args   An array of arguments. @see wp_nav_menu()
	 */
	public function end_el( &$output, $item, $depth = 0, $args = array() ) {
		$output .= "\n";
	}
}