wp-includes/class-wp-application-passwords.php:53Checks if application passwords are being used by the site.
bool public static function is_in_use() { $network_id = get_main_network_id(); return (bool) get_network_option( $network_id, self::OPTION_KEY_IN_USE ); }Introduced in 5.6.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-application-passwords.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.