private function makeRegionCityLabelsUnique(&$row)
    {
        // remove the location separator from the region/city/country we get from the query
        foreach ($this->dimensions as $column) {
            $row[$column] = str_replace(self::LOCATION_SEPARATOR, '', $row[$column]);
        }

        if (!empty($row[self::REGION_FIELD])) {
            $row[self::REGION_FIELD] = $row[self::REGION_FIELD] . self::LOCATION_SEPARATOR . $row[self::COUNTRY_FIELD];
        }

        if (!empty($row[self::CITY_FIELD])) {
            $row[self::CITY_FIELD] = $row[self::CITY_FIELD] . self::LOCATION_SEPARATOR . $row[self::REGION_FIELD];
        }
    }