@Override
 public void remove(Entry entry) throws Exception {
   if (!entries.containsKey(entry.getId())) {
     throw new DBException("Entry not found");
   }
   long logid = entry.getLog().getId();
   Log log = logDB.get(logid);
   log.removeEntry(entry);
   logDB.update(log);
   entries.remove(entry.getId());
 }
  @Override
  public Entry add(Entry entry) throws Exception {
    if (entries.containsValue(entry)) {
      throw new DBException("Entry is already in the collection");
    }
    entry.setId(idCounter);
    entries.put(idCounter, entry);
    idCounter++;

    Log log = entry.getLog();
    log.addEntry(entry);
    logDB.update(log);
    return entry;
  }