  @Test
  public void makeTransactionWithWrongAddress() {


    String firstAddress= "firstAddress";
    String secondAddresss= "secondAddress";



    Wallet secondWallet = new Wallet();
    secondWallet.setBalance(0);



    Long value = 30000L;
    String address = "some address";

    when(walletRepository.findByAddress(firstAddress)).thenReturn(null);
    when(walletRepository.findByAddress(secondAddresss)).thenReturn(secondWallet);

    BillingService billingService = new BillingService(walletRepository,transactionRepository);
    try {
      Transaction transaction = billingService.makeTransaction(firstAddress, secondAddresss, value);
      fail(); // Should have thrown an exception
    } catch (Exception ex){ex.printStackTrace();}

  }