is_dynamic_sidebar бяка на Codex?

Вот http://codex.wordpress.org/Function_Reference/is_dynamic_sidebar официальное описание функции. Написано, что вх.параметров нет.
Как нет, когда в исходнике widgets.php:

/**
 * Display dynamic sidebar.
 *
 * By default it displays the default sidebar or 'sidebar-1'. The 'sidebar-1' is
 * not named by the theme, the actual name is '1', but 'sidebar-' is added to
 * the registered sidebars for the name. If you named your sidebar 'after-post',
 * then the parameter $index will still be 'after-post', but the lookup will be
 * for 'sidebar-after-post'.
 *
 * It is confusing for the $index parameter, but just know that it should just
 * work. When you register the sidebar in the theme, you will use the same name
 * for this function or "Pay no heed to the man behind the curtain." Just accept
 * it as an oddity of WordPress sidebar register and display.
 *
 * @since 2.2.0
 *
 * @param int|string $index Optional, default is 1. Name or ID of dynamic sidebar.
 * @return bool True, if widget sidebar was found and called. False if not found or not called.
 */
function dynamic_sidebar($index = 1) {