### Question:
MongoTopologyDao extends MongoDao<Topology, String> implements TopologyDao { @Override public boolean exists(String id, String userId) { return findById(id, userId) != null; } @Inject  MongoTopologyDao(Datastore datastore); @Override boolean exists(String id, String userId); @Override List<Topology> findAll(String userId); @Override Topology findById(String id, String userId); @Override Topology findByName(String name, String userId); @Override Topology save(Topology topology, String userId); @Override Topology update(Topology topology, String userId); @Override void delete(Topology topology, String userId); @Override void deleteById(String id, String userId);  }### Answer:
@Test public void checkIfTopologyExistsForUser() { assertTrue("Exists should return true for an entity with a valid ID", topologyDao.exists("first", "user1")); assertFalse("Exists should return false for an entity with a invalid ID", topologyDao.exists("second", "user1")); }
@Test public void checkIfTopologyExistsForAnonymous() { assertTrue("Exists should return true for an entity with a valid ID", topologyDao.exists("fourth", null)); assertFalse("Exists should return false for an entity with a invalid ID", topologyDao.exists("second", null)); }