@Override
    public Config rewrite(String name, Config config) {
      Map<String, String> newConfigMap = new HashMap<>(config);
      newConfigMap.remove(CONFIG_KEY);
      return new MapConfig(newConfigMap);
    }
Removes config entry for the key {@link #CONFIG_KEY} and {@link #NEW_CONFIG_KEY}.
samza-core/src/test/java/org/apache/samza/util/TestConfigUtil.java