### Question:
Utils { public static String applicationMessageIdToString(ApplicationMessageID transactionId) { String txId = "0.0." + transactionId.getAccountID().getAccountNum() + "-" + transactionId.getValidStart().getSeconds() + "-" + transactionId.getValidStart().getNanos(); return txId; }  static String timestampToDate(long seconds, int nanos); static String timestampToTime(long seconds, int nanos); static String applicationMessageIdToString(ApplicationMessageID transactionId); static String transactionIdToString(TransactionId transactionId); static Credit creditFromCreditBPM(CreditBPM creditBPM, String threadId); static CreditBPM creditBPMFromCredit(Credit credit); static Settlement settlementFromSettleProposeBPM(SettleProposeBPM settleProposeBPM, String threadId); static ApplicationMessageID applicationMessageIdFromString(String appMessageId); static String getThreadId(); static Money moneyFromSettlement(Settlement settlement); static ResponseEntity<SettlementRest> serverError();  }### Answer:
@Test public void testApplicationMessageIdToString() { ApplicationMessageID.Builder applicationMessageID = ApplicationMessageID.newBuilder(); applicationMessageID.setAccountID(AccountID.newBuilder().setAccountNum(2)); applicationMessageID.setValidStart(Timestamp.newBuilder().setSeconds(10).setNanos(20)); String appliString = Utils.applicationMessageIdToString(applicationMessageID.build()); assertEquals("0.0.2-10-20", appliString); }