protected function getApiEndpoint($publisherId, $listExternalId)
    {
        return sprintf(self::EB_API_ENDPOINT, $publisherId, $listExternalId, $this->apiKey, $this->apiSecret);
    }
protected function getApiEndpoint($publisherId, $listExternalId)
    {
        return sprintf(self::EB_API_ENDPOINT, $publisherId, $listExternalId, $this->apiKey, $this->apiSecret);
    }
@param int    $publisherId The publisher Id
@param string $listExternalId The publisher list external Id

@return string