Piwik\Plugins\UsersManager\API::isUserTheOnlyUserHavingSuperUserAccess PHP Method

    private function isUserTheOnlyUserHavingSuperUserAccess($userLogin)
    {
        $superUsers = $this->getUsersHavingSuperUserAccess();
        return 1 >= count($superUsers) && Piwik::hasTheUserSuperUserAccess($userLogin);
    }