private function validateJob(JobInfo $job)
 {
     if ($job->getContentType() == self::CSV && !$this->apiVersionIsAtLeast($this->endpoint, 17.0)) {
         throw new Exception("Content Type 'CSV' only supported in API 17.0 and higher.");
     }
     if ($job->getOpertion() == "delete" && !$this->apiVersionIsAtLeast($this->endpoint, 18.0)) {
         throw new Exception("Bulk API 'Delete' operation only supported in API 18.0 and higher.");
     }
     if ($job->getOpertion() == "hardDelete" && !$this->apiVersionIsAtLeast($this->endpoint, 19.0)) {
         throw new Exception("Bulk API 'Hard Delete' operation only supported in API 19.0 and higher.");
     }
     if (in_array($job->getContentType(), array(self::ZIP_CSV, self::ZIP_XML)) && !$this->apiVersionIsAtLeast($this->endpoint, 20.0)) {
         throw new Exception("Zipped Content Types only supported in API 20.0 and higher.");
     }
 }