docs: public Response getTransactionsKeys(String key, int account) {
          Response operation = new Response();
          if (walletDAO.hasWallet(key)) {
              V2Wallet wallet = wallets.getWallet(key);
              if (wallet == null) {
                  wallet = init(key);
              }
              operation.setPayload(wallet.getTransactionsKeys(account));
          } else {
              operation.addError(new Error(3));
          }
          return operation;
      }