wp-admin/includes/deprecated.php:1207This was once used to kick-off the Theme Updater.
$theme$feedbackoptional''function wp_update_theme($theme, $feedback = '') { _deprecated_function( __FUNCTION__, '3.7.0', 'new Theme_Upgrader();' ); if ( !empty($feedback) ) add_filter('update_feedback', $feedback); require ABSPATH . 'wp-admin/includes/class-wp-upgrader.php'; $upgrader = new Theme_Upgrader(); return $upgrader->upgrade($theme);}Introduced in 2.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.