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

        $data = Values::of(array(
            'AvailableAddOnSid' => $availableAddOnSid,
            'AcceptTermsOfService' => Serialize::booleanToString($acceptTermsOfService),
            'Configuration' => Serialize::jsonObject($options['configuration']),
            'UniqueName' => $options['uniqueName'],
        ));

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

        return new InstalledAddOnInstance($this->version, $payload);
    }