code: def _format_auth_line(key, enc, comment, options):
      '''
      Properly format user input.
      '''
      line = ''
      if options:
          line += '{0} '.format(','.join(options))
      line += '{0} {1} {2}\n'.format(enc, key, comment)
      return linf _format_auth_line(key, enc, comment, options):
      '''
      Properly format user input.
      '''
      line = ''
      if options:
          line += '{0} '.format(','.join(options))
      line += '{0} {1} {2}\n'.format(enc, key, comment)
      return line
docs: Properly format user input.