@Override
  public void close() throws HiveSQLException {
    if (!embedded) {
      cleanup(OperationState.CLOSED);
      cleanupOperationLog(0);
    }
  }
Returns the current UGI on the stack

@return UserGroupInformation

@throws HiveSQLException
service/src/java/org/apache/hive/service/cli/operation/SQLOperation.java