public function getDefaultGroup($usePosix = false)
    {
        $defaultPermissions = $this->getDefaultPermissions();

        $group = $defaultPermissions['group'];
        if (empty($group) && $usePosix) {
            $group = function_exists('posix_getegid') ? posix_getegid() : null;
        }

        if (empty($group)) {
            return false;
        }

        return $group;
    }