WordPress Version: 4.9
/**
* Retrieve post ancestors.
*
* This is no longer needed as WP_Post lazy-loads the ancestors
* property with get_post_ancestors().
*
* @since 2.3.4
* @deprecated 3.5.0 Use get_post_ancestors()
* @see get_post_ancestors()
*
* @param WP_Post $post Post object, passed by reference (unused).
*/
function _get_post_ancestors(&$post)
{
_deprecated_function(__FUNCTION__, '3.5.0');
}