code: def AddArguments(cls, argument_group):
      
      argument_group.add_argument(
          '--fields', dest='fields', type=str, action='store',
          default=cls._DEFAULT_FIELDS, help=(
              'Defines which fields should be included in the output.'))
      argument_group.add_argument(
          '--additional_fields', dest='additional_fields', type=str,
          action='store', default='', help=(
              'Defines extra fields to be included in the output, in addition to'
              ' the default fields, which are {0:s}.'.format(
                  cls._DEFAULT_FIELDS)))
      argument_group.add_argument(
          '--timestamp_format', dest='timestamp_format', type=str,
          action='store', default=cls._DEFAULT_TIMESTAMP_FORMAT, help=(
              'Set the timestamp format that will be used in the datetime'
              'column of the XLSX spreadsheet.'))
docs: Adds command line arguments the helper supports to an argument group.
  
      This function takes an argument parser or an argument group object and adds
      to it all the command line arguments this helper supports.
  
      Args:
        argument_group (argparse._ArgumentGroup|argparse.ArgumentParser):
            argparse group.