public function recognize($audio, array $options = [])
    {
        $results = [];
        $response = $this->connection->recognize(
            $this->formatRequest($audio, $options)
        );

        if (!isset($response['results'])) {
            return $results;
        }

        foreach ($response['results'] as $result) {
            $results[] = new Result($result);
        }

        return $results;
    }