public function call($methodName = null)
    {
        $this->setMethod($methodName);

        $curl = $this->getCurl();
        $curl->setParameters($this->getParameters());

        $this->log($this->getParameters(), 'Request to PayPal');

        $response = $curl->execute();

        $this->log($response, 'Response from PayPal');

        $this->validateResponse($response);

        return $response;
    }