protected function enrichWithMany(array $rows)
    {
        $manyFields = $this->getManyFields();
        $idToData   = [];
        foreach ($rows as $row) {
            foreach ($manyFields as $manyField) {
                $row[$manyField] = [];
            }
            $idToData[$row['id']] = $row;
        }
        foreach ($manyFields as $manyField) {
            $this->enrichWithManyField($idToData, $manyField);
        }
        return array_values($idToData);
    }