@Test
  public void testGetCoordinatorStreamStoreFactoryWithDefaultSystem() {
    Optional<MetadataStoreFactory> metadataStoreFactory =
        LocalApplicationRunner.getDefaultCoordinatorStreamStoreFactory(new MapConfig(ImmutableMap.of(JobConfig.JOB_DEFAULT_SYSTEM, "test-system")));
    assertTrue(metadataStoreFactory.isPresent());
  }
Default metadata store factory should not be null if default system defined and the default
ZkJobCoordinator is used.
samza-core/src/test/java/org/apache/samza/runtime/TestLocalApplicationRunner.java