Make real Test for BO only

src/main/java/fr/eni/demo/bll/ClientService.java

@@ -1,23 +1,10 @@
 package fr.eni.demo.bll;
 
 import fr.eni.demo.bo.Client;
-import fr.eni.demo.dal.ClientRepository;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Service;
 
 import java.util.Optional;
 
-@Service
-public class ClientService {
-
-  @Autowired
-  private ClientRepository clientRepository;
-
-  public void add(Client client) {
-    clientRepository.save(client);
-  }
-
-  public Optional<Client> findById(Long clientId) {
-    return clientRepository.findById(clientId);
-  }
+public interface ClientService {
+  void add(Client client);
+  Optional<Client> findById(Long clientId);
 }