PiwikTracker::setRegion PHP Method

    public function setRegion($region)
    {
        $this->region = $region;
        return $this;
    }

 private function doPingRequest(\PiwikTracker $tracker, $pingTime, $changeDimensionValues)
 {
     if ($changeDimensionValues) {
         $tracker->setUserAgent(self::CHANGED_USER_AGENT);
         $tracker->setBrowserLanguage(self::CHANGED_BROWSER_LANGUAGE);
         $tracker->setCountry(self::CHANGED_COUNTRY);
         $tracker->setRegion(self::CHANGED_REGION);
     }
     $tracker->setForceVisitDateTime($pingTime);
     $response = $tracker->doPing();
     Fixture::checkResponse($response);
     return $response;
 }