class_docstr: The ``trove_classifiers`` package is the official way of validating classifiers,
  however this package might not be always available.
  As a workaround we can still download a list from PyPI.
  We also don't want to be over strict about it, so simply skipping silently is an
  option (classifiers will be validated anyway during the upload to PyPI).
code: def __init__(self):
      self.downloaded = None
      self._skip_download = False
      # None => not cached yet
      # False => cache not available
      self.__name__ = "trove_classifier"
  
imports: import logging
  import os
  import re
  import string
  import typing
  from itertools import chain
label_desc: Use image node_id 1 to create a new _TroveClassifier object  with example: obj = _TroveClassifier()