Mocking outer class with Mockito

I am trying to mock outer class but always get NullPointerException. I have class:

@Service
public class ProductService {
    @Autowired
    public ProductService (AutoService autoService, DocumentService documentService, TimeService timeService) {
        this(autoService, documentService, batchtimeService, new History());
    }

inside this class I have:

public class PublishTimeProcess implements TimeProcess<Product> {

with constructor:

public PublishTimeProcess (Calendar minTime) {
    this.minTime= minTime;
}

and method:

@Override
public void startProcess(List<Product> products) {

which I would like to test.

So I mocked:

@Mock
ProductService productService;

and in @Before method I did:

@Before
public void setUp(){
    publishTimeProcess = productService. new PublishTimeProcess(minTime);
}

and then in @Test method I just try to call publishTimeProcess.startProcess(products);

but then NPE happens because publishTimeProcess is always null. Is there a way to mock outer class but create inner class anyway?

@Edit, forgot to mention that I don't use PowerMockito