public boolean addItem(String contratID, Item item) {
    Contrat contrat = null;

    User currentUser = manager.getUserManager().getCurrentUser();
    if (currentUser == null) {
      System.err.println("no user logged");
      return false;
    }
    String publicKey = currentUser.getKeys().getPublicKey().toString(16);

    for (Contrat c : deals.get(publicKey)) {
      if (c.getId().equals(contratID)) {
        contrat = c;
        break;
      }
    }
    if (contrat == null) {
      Printer.printError(this, "addItem", "Contrat doesn't exist !");
      return false;
    }
    return contrat.addItem(item);
  }