public function create($certificateData, $options = array()) {
        $options = new Values($options);

        $data = Values::of(array(
            'CertificateData' => $certificateData,
            'FriendlyName' => $options['friendlyName'],
            'DeviceSid' => $options['deviceSid'],
        ));

        $payload = $this->version->create(
            'POST',
            $this->uri,
            array(),
            $data
        );

        return new CertificateInstance($this->version, $payload, $this->solution['fleetSid']);
    }