/**
  * @return null|string
  */
 public function getStatus()
 {
     $status = parent::getStatus();
     if ($status == static::ENABLED && $this->availableOn) {
         $currentTime = DateTimeHelper::currentTimeStamp();
         $availableOn = $this->availableOn->getTimestamp();
         $expiresOn = $this->expiresOn ? $this->expiresOn->getTimestamp() : null;
         if ($availableOn <= $currentTime && (!$expiresOn || $expiresOn > $currentTime)) {
             return static::LIVE;
         } else {
             if ($availableOn > $currentTime) {
                 return static::PENDING;
             } else {
                 return static::EXPIRED;
             }
         }
     }
     return $status;
 }