/**
* Clear the registry.
*
* TestUsers created by this class will not be deleted, but any handles
* to existing immutable TestUsers will be deleted, ensuring these users
* are not reused. We don't reset the counter or random string by design.
*
* @since 1.28
*
* @param string[] $groups Groups the test user should be added to.
* @return TestUser
*/
public static function clear()
{
self::$testUsers = [];
}
