private void populateConf(Configuration target, Properties properties, String source) {
    for (Entry<Object, Object> entry : properties.entrySet()) {
      String key = (String) entry.getKey();
      String val = conf.get(key);
      if (val != null) {
        target.set(key, val, source);
      }
    }
  }
Copy config files for the tarball.
llap-server/src/java/org/apache/hadoop/hive/llap/cli/service/AsyncTaskCopyConfigs.java