@Override
  public ConfigLoader getLoader(Config config) {
    String path = config.get(PATH_KEY);

    if (path == null) {
      throw new SamzaException("path is required to read config from properties file");
    }

    return new PropertiesConfigLoader(path);
  }
ConfigLoaderFactory which initialize {@link PropertiesConfigLoader} with properties file path specified in
job.config.loader.properties.path.
samza-core/src/main/java/org/apache/samza/config/loaders/PropertiesConfigLoaderFactory.java