@Test
  public void logSuccessfulResponse() {
    log.logResponse(status);
    assertTrue(mock_simulator.getLastLog().equals("Response:  " + status.toString()));

    // make emma happy
    status.isInvalidPIN();
    status.getMessage();
  }
 @Test
 public void logEnvelopeAccepted() {
   log.logEnvelopeAccepted();
   assertTrue(mock_simulator.getLastLog().equals("Envelope:  received"));
 }
 @Test
 public void logCashDispensed() {
   Money money = new Money(22, 55);
   log.logCashDispensed(money);
   assertTrue(mock_simulator.getLastLog().equals("Dispensed: " + money.toString()));
 }
 @Test
 public void logSend() {
   Message message = new Message(1, new Card(2), 3, 4, 5, new Money(6));
   log.logSend(message);
   assertTrue(mock_simulator.getLastLog().equals("Message:   " + message.toString()));
 }