public static function buildHttpClient(
        $url = NULL,
        $username = NULL,
        $password = NULL,
        $contentType = self::CONTENT_JSON_API,
        $language = self::HEADER_LOCALE
    )
    {
        $client = new Client($url);
        $client->setHead([
            'Accept: ' . $contentType,
            'Accept-Language: ' . $language,
            'Content-Type: application/vnd.api+json'
        ]);

        if (is_scalar($username) && is_scalar($password)) {
            $client->setOptions([CURLOPT_HTTPAUTH, CURLAUTH_ANY]);
            $client->setOption(CURLOPT_USERPWD, $username . ':' . $password);
        }

        return $client;
    }