old_contents: '''
  anorack's private modules
  '''
  
  type(...)  # Python >= 3 is required
  
new_contents: '''
  anorack's private modules
  '''
  
  import sys
  
  type(...)  # Python >= 3 is required
  if sys.version_info < (3, 2):
      raise RuntimeError('Python >= 3.2 is required')
  
  __all__ = []
  
  # vim:ts=4 sts=4 sw=4 et
  
subject: add explicit check against Python 3.0/3.1.