private function makeCall($actionVerb, $params = "")
{
$myTimeStamp = \gmdate(DATE_RFC1123);
$sig = $this->_apiToken . ':' . $myTimeStamp . ':' . $actionVerb . ':' . $this->_apiSecret;
$sigHash = \hash("sha256", $sig);
$myHeaders = array("x-ShareASale-Date: {$myTimeStamp}", "x-ShareASale-Authentication: {$sigHash}");
$ch = \curl_init();
$url = $this->_apiServer . "affiliateId=" . $this->_affiliateId . "&token=" . $this->_apiToken . "&version=" . $this->_apiVersion . "&action=" . $actionVerb . $params;
\curl_setopt($ch, CURLOPT_URL, $url);
\curl_setopt($ch, CURLOPT_HTTPHEADER, $myHeaders);
\curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
\curl_setopt($ch, CURLOPT_HEADER, 0);
$returnResult = \curl_exec($ch);
\curl_close($ch);
return $returnResult;
}