public function find($productFamilyId)
    {
        $service       = $this->getService();
        $response      = $service->request('product_families/' . $productFamilyId . '/coupons/find', 'GET', NULL, $this->_params);
        $responseArray = $this->getResponseArray($response);

        // status code must be 200, otherwise the code in $this->setCode() was not found
        if (!$this->isError() && '200' == $response->getStatusCode()) {
            $this->_data = $responseArray['coupon'];
        } else {
            $this->_data = array();
        }

        return $this;
    }