content: package za.ac.cput.database;
  
  import za.ac.cput.domain.User;
  import za.ac.cput.repositories.UserRepository;
  
  import java.util.*;
  //No real database connection yet!
  //This satisfies the Future-Proofing requirement from Assignment 11.
  //Later (in future versions), you can update save(), findById(), etc. to use JDBC, Hibernate, Spring
  //Data, or another framework.
  
  public class DatabaseUserRepository implements UserRepository {
      @Override
      public void save(User entity) {
          throw new UnsupportedOperationException("Database storage not yet implemented.");
      }
  
      @Override
      public Optional<User> findById(String id) {
          throw new UnsupportedOperationException("Database storage not yet implemented.");
      }
  
      @Override
      public List<User> findAll() {
          throw new UnsupportedOperationException("Database storage not yet implemented.");
      }
  
      @Override
      public void delete(String id) {
          throw new UnsupportedOperationException("Database storage not yet implemented.");
      }
  }
  