PayPal\Api\Authorization::setValidUntil PHP Method

    public function setValidUntil($valid_until)
    {
        $this->valid_until = $valid_until;
        return $this;
    }

 public function setup()
 {
     $authorization = new Authorization();
     $authorization->setCreateTime(self::$create_time);
     $authorization->setUpdateTime(self::$update_time);
     $authorization->setId(self::$id);
     $authorization->setState(self::$state);
     $authorization->setParentPayment(self::$parent_payment);
     $authorization->setValidUntil(self::$valid_until);
     $authorization->setClearingTime(self::$clearing_time);
     $this->authorizations['partial'] = $authorization;
     $this->authorizations['full'] = self::createAuthorization();
 }