### Question:
OfOverlayNodeListener implements DataTreeChangeListener<OfOverlayNodeConfig>, AutoCloseable { @Override public void close() throws Exception { if (listenerRegistration != null) { listenerRegistration.close(); } } OfOverlayNodeListener(DataBroker dataProvider, SwitchManager switchManager); @Override void onDataTreeChanged(Collection<DataTreeModification<OfOverlayNodeConfig>> changes); @Override void close();  }### Answer:
@Test public void constructorTest() throws Exception { listener.close(); verify(listenerRegistration).close(); }