code: protected boolean isDurable()
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
          {
              SibTr.entry(this, tc, "isDurable");
              SibTr.exit(this, tc, "isDurable", Boolean.valueOf(durable));
          }
          return durable; // F001333-14610
      }
docs: Is this a durable subscription state
  
  @return isDurable