public function createOrUpdate($name, array $fields)
    {
        $url = $this->client->url . "/rest/v1/customobjects/".$name.".json";
        $response = $this->post($url, [
            'action' => 'createOrUpdate',
            'input' => $fields
        ]);

        if (!$response->success) {
            throw new MarketoApiException('Error syncing custom object: ' . $response->errors[0]->message);
        }
    }