private static Optional<ExternalContext> buildExternalContext(@SuppressWarnings("unused") Config config) {
    /*
     * By default, use an empty ExternalContext here. In a custom fork of Samza, this can be implemented to pass
     * a non-empty ExternalContext. Only config should be used to build the external context. In the future, components
     * like the application descriptor may not be available.
     */
    return Optional.empty();
  }
{@link ApplicationRunnerMain} was designed for deploying {@link SamzaApplication} in yarn
and doesn't work for in standalone.

This runner class is built for standalone failure tests and not recommended for general use.
samza-test/src/main/java/org/apache/samza/test/integration/LocalApplicationRunnerMain.java