public function insertGetId(array $values, $sequence = null)
    {
        $result = $this->collection->insertOne($values);

        if (1 == (int) $result->isAcknowledged()) {
            if (is_null($sequence)) {
                $sequence = '_id';
            }

            // Return id
            return $sequence == '_id' ? trim($result->getInsertedId()) : $values[$sequence];
        }

        return null;
    }