code: @Override
    public void close() throws HiveSQLException {
      try {
        acquire(true);
        cancelDelegationToken();
      } finally {
        try {
          super.close();
        } finally {
          try {
            FileSystem.closeAllForUGI(sessionUgi);
          } catch (IOException ioe) {
            throw new HiveSQLException("Could not clean up file-system handles for UGI: "
                + sessionUgi, ioe);
          }
        }
      }
    }
docs: Close the file systems for the session and remove it from the FileSystem cache.
  Cancel the session's delegation token and close the metastore connection