+ /**
+ * Filter a menu item's starting output.
+ *
+ * The menu item's starting output only includes $args->before, the opening <a>,
+ * the menu item's title, the closing </a>, and $args->after. Currently, there is
+ * no filter for modifying the opening and closing <li> for a menu item.
+ *
+ * @since 3.0.0
+ *
+ * @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 arguments. @see wp_nav_menu()
+ */