private function getConfigPermission(RoleSecurityIdentity $sid, $operation, $subject = null, $class = null, $field = null)
    {
        $sps = $this->getConfigPermissions();
        $field = null !== $field ? PermissionProviderInterface::CONFIG_FIELD : null;
        $fieldAction = PermissionUtils::getMapAction($field);
        $pc = null;

        if (isset($sps[PermissionProviderInterface::CONFIG_CLASS][$fieldAction][$operation])) {
            $sp = $sps[PermissionProviderInterface::CONFIG_CLASS][$fieldAction][$operation];
            $pc = new PermissionChecking($sp, $this->isConfigGranted($sid, $operation, $subject, $class), true);
        }

        return $pc;
    }