code: def add_format(self, parser, default=Encoding.PEM, help_text=None, opts=None):
          
  
          if opts is None:
              opts = ['-f', '--format']
          if help_text is None:
              help_text = 'The format to use ("ASN1" is an alias for "DER", default: %(default)s).'
          help_text = help_text % {'default': default.name}
          parser.add_argument(*opts, metavar='{PEM,ASN1,DER}', default=default,
                              action=FormatAction, help=help_text)
docs: Add the --format option.