protected function _getAmazonClient($aConfig = array())
    {
        if ($this->_oAmazonClient === null) {
            $aConfig = array_merge(
                $aConfig,
                array(
                    'merchant_id' => $this->getConfig()->getConfigParam('sAmazonSellerId'),
                    'access_key' => $this->getConfig()->getConfigParam('sAmazonAWSAccessKeyId'),
                    'secret_key' => $this->getConfig()->getConfigParam('sAmazonSignature'),
                    'client_id' => $this->getConfig()->getConfigParam('sAmazonLoginClientId'),
                    'region' => $this->getConfig()->getConfigParam('sAmazonLocale')
                )
            );

            $this->_oAmazonClient = new Client($aConfig);
            $this->_oAmazonClient->setSandbox((bool)$this->getConfig()->getConfigParam('blAmazonSandboxActive'));
            $this->_oAmazonClient->setLogger($this->_getLogger());
        }

        return $this->_oAmazonClient;
    }