code: public JsBus getBus() {
          if (TraceComponent.isAnyTracingEnabled()
              && tc.isEntryEnabled())
              SibTr.entry(tc, "getBus");
          JsBus jsBus = (JsBus) _engine.getBus();
          if (TraceComponent.isAnyTracingEnabled()
              && tc.isEntryEnabled())
              SibTr.exit(tc, "getBus", jsBus);
          return jsBus;
      }
docs: Gets a reference to the actual bus which this messaging engine belongs
  to.
  
  @return