private void updateConfig(Cluster cluster, String configType, Function<String, String> contentUpdater) throws AmbariException {
    Config config = cluster.getDesiredConfigByType(configType);
    if (config == null)
      return;
    if (config.getProperties() == null || !config.getProperties().containsKey("content"))
      return;

    String content = config.getProperties().get("content");
    content = contentUpdater.apply(content);
    updateConfigurationPropertiesForCluster(cluster, configType, Collections.singletonMap("content", content), true, true);
  }
@return a map describing the new LDAP configuration key to the old ambari.properties property name
ambari-server/src/main/java/org/apache/ambari/server/upgrade/UpgradeCatalog270.java