docs: public void dereferenceControllable()
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) 
        SibTr.entry(tc, "dereferenceControllable");
      _sourceStream = null;
      _sourceStreamSet = null;
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) 
        SibTr.exit(tc, "dereferenceControllable");
    }