class_docstr: This decorator class ensures seamless namenode failover and retry, when an HDFS call fails
  due to StandbyException, up to a maximum retry.
docstr: Support usage of decorator on instance methods. 
code: def __get__(self, obj, obj_type):
      """Support usage of decorator on instance methods."""
      # This avoids needing to cache the `obj` as member variable
      return functools.partial(self.__call__, obj)
  
imports: import functools
  import inspect
  import logging
  import os
  from distutils.version import LooseVersion
  from xml.etree import ElementTree
  import pyarrow
  import six
  from pyarrow.hdfs import HadoopFileSystem
  from pyarrow.lib import ArrowIOError
  from six.moves.urllib.parse import urlparse
label_desc: Use image node_id 2 for calling the namenode_failover obj's underlying member method code with example usage: obj.__get__(obj, obj_type) and returns: functools