/**
  * Declares an association between this object and a SystemEventSubscription object.
  *
  * @param                  SystemEventSubscription $v
  * @return                 SystemEventInstanceMessage The current object (for fluent API support)
  * @throws PropelException
  */
 public function setSystemEventSubscription(SystemEventSubscription $v = null)
 {
     if ($v === null) {
         $this->setSystemEventSubscriptionId(NULL);
     } else {
         $this->setSystemEventSubscriptionId($v->getId());
     }
     $this->aSystemEventSubscription = $v;
     // Add binding for other direction of this n:n relationship.
     // If this object has already been added to the SystemEventSubscription object, it will not be re-added.
     if ($v !== null) {
         $v->addSystemEventInstanceMessage($this);
     }
     return $this;
 }