@VisibleForTesting
  void startKsql(final KsqlConfig ksqlConfigWithPort) {
    cleanupOldState();
    initialize(ksqlConfigWithPort);
  }
@Test
  public void shouldConfigureRocksDBConfigSetter() {
    // When:
    app.startKsql(ksqlConfig);

    // Then:
    verify(rocksDBConfigSetterHandler).accept(ksqlConfig);
  }