### Question:
CanonCamera { public Optional<EdsCameraRef> getCameraRef() { return Optional.ofNullable(cameraRef.get()); } CanonCamera();  CanonCamera(final String serialNumber); T dispatchCommand(T command); Optional<EdsCameraRef> getCameraRef(); CanonCamera setCameraRef(final EdsCameraRef cameraRef); Optional<String> getSerialNumber(); void setSerialNumber(final String serialNumber); Optional<CommandBuilderReusable> getCommandBuilderReusable(); void setCommandBuilderReusable(final CommandBuilderReusable commandBuilderReusable); Optional<Duration> getDefaultTimeout(); CanonCamera setDefaultTimeout(final Duration defaultTimeout); Event getEvent(); Shoot getShoot(); LiveView getLiveView(); Property getProperty(); GenericCommand<R> sendGenericCommandAsync(final GenericCommand<R> command); GenericCommand<R> sendGenericCommandAsync(final CallableCommand<R> callableCommand); CameraCommand sendCameraCommandAsync(final EdsCameraCommand cameraCommand); CameraCommand sendCameraCommandAsync(final EdsCameraCommand cameraCommand, final NativeEnum<? extends Number> param); CameraCommand sendCameraCommandAsync(final EdsCameraCommand cameraCommand, final long inParam); StatusCommand sendStatusCommandAsync(final EdsCameraStatusCommand statusCommand); IsConnectedCommand isConnectedAsync(); OpenSessionCommand openSession(); OpenSessionCommand openSession(final OpenSessionOption option); CloseSessionCommand closeSession(); CloseSessionCommand closeSession(final CloseSessionOption option); @Override String toString();  }### Answer:
@Test void getCameraRef() { Assertions.assertFalse(cameraDefaultConstructor.getCameraRef().isPresent()); Assertions.assertFalse(cameraWithSerialNumber.getCameraRef().isPresent()); }