wp-includes/deprecated.php:2156Serves as an alias of wp_unregister_sidebar_widget().
$idint|stringfunction unregister_sidebar_widget($id) { _deprecated_function( __FUNCTION__, '2.8.0', 'wp_unregister_sidebar_widget()' ); return wp_unregister_sidebar_widget($id);}Introduced in 2.2.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.