### Question:
NeutronMapper implements ClusteredDataTreeChangeListener<Neutron>, AutoCloseable { @Override public void close() { registerDataTreeChangeListener.close(); } NeutronMapper(DataBroker dataProvider, EndpointService epService, BaseEndpointService baseEpService,
        @Nullable IpPrefix metadataIpPrefix, long metadataTcpPort); @Override void onDataTreeChanged(@Nonnull Collection<DataTreeModification<Neutron>> changes); @Override void close();  }### Answer:
@Test public void testConstructor() throws IOException { DataBroker dataBrokerSpy = spy(dataBroker); NeutronMapper other = new NeutronMapper(dataBrokerSpy, epService, baseEpService, METADATA_IP_PREFIX, METADATA_IPV4_SERVER_PORT); verify(dataBrokerSpy).registerDataTreeChangeListener(new DataTreeIdentifier<>( LogicalDatastoreType.CONFIGURATION, InstanceIdentifier.builder(Neutron.class).build()), other); other.close(); }