public static function removeRoColumns(array $rules, $engine)
    {
        foreach ($rules as $index => $subrules) {
            if (is_array($subrules)) {
                $eback         = $engine->getEvidence();
                $engine->setEvidence($engine->getEvidence().'-polozka');
                $rules[$index] = self::removeRoColumns($subrules, $engine);
                $engine->setEvidence($eback);
            } else {
                $columnInfo = $engine->getColumnInfo($subrules);
                if ($columnInfo['isWritable'] == 'false') {
                    unset($rules[$index]);
                }
            }
        }
        return $rules;
    }