docs: public String getId()
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) 
        SibTr.entry(tc, "getId");
      String id = _sourceStream.getID();
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) 
        SibTr.exit(tc, "getId", id);
      return id; 
    }