private void addMethodTime(Method method, long timeTaken) {
    String methodStr = getMethodString(method);
    while (true) {
      Long curTime = metaCallTimeMap.get(methodStr), newTime = timeTaken;
      if (curTime != null && metaCallTimeMap.replace(methodStr, curTime, newTime + curTime)) break;
      if (curTime == null && (null == metaCallTimeMap.putIfAbsent(methodStr, newTime))) break;
    }
  }
Returns the UGI for the current user.
@return the UGI for the current user.
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/RetryingMetaStoreClient.java