private function createContentKeyObject($keySeed, $keyId)
 {
     if (!$keyId) {
         throw new KalturaAPIException(KalturaErrors::MISSING_MANDATORY_PARAMETER, "keyId");
     }
     $contentKeyVal = kPlayReadyAESContentKeyGenerator::generatePlayReadyContentKey($keySeed, $keyId);
     $contentKey = new PlayReadyContentKey();
     $contentKey->setKeyId($keyId);
     $contentKey->setContentKey($contentKeyVal);
     return $contentKey;
 }