code: public void addSubscriptionToDelete(SubscriptionItemStream stream)
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(tc, "addSubscriptionToDelete", stream);
          synchronized (deletableSubscriptions)
          {
              deletableSubscriptions.add(stream);
          }
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(tc, "addSubscriptionToDelete");
      }
docs: Add a subscription to the list of subscriptions to be deleted.