source: class TransactionManagerTest {
  
      private static final String ACCOUNT;
      private static final String MERCHANT;
      private static final Integer AMOUNT;
      private static final Transaction TRANSACTION;
  
      @Test
      public void initialTransactionTest() {
  
target:         FunctionTestHarness harness = FunctionTestHarness.test(ignore -> new TransactionManager(), MANAGER_FN, "id");
  
          Assert.assertThat(
              harness.invoke(TRANSACTION),
              sent(
                      messagesTo(new Address(FRAUD_FN, ACCOUNT), equalTo(QueryFraud.getDefaultInstance())),
                      messagesTo(new Address(MERCHANT_FN, MERCHANT), equalTo(QueryMerchantScore.getDefaultInstance()))));
      }
  
  }