public function update($data, $override = null)
    {
        if (func_num_args() == 2) {
            $override['id'] = $data;
            $data = $override;
        }

        $response = $this->ontraport->put(
            $this->getNamespace(), $this->toArray($data)
        );

        return $this->ontraport->item($this, $response);
    }