@classmethod
def AddArguments(cls, argument_group):
    """Adds command line arguments 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.
    """
    argument_group.add_argument('--preferred_year', '--preferred-year',
        dest='preferred_year', type=int, action='store', default=None,
        metavar='YEAR', help=
        "When a format's timestamp does not include a year, e.g. syslog, use this as the initial year instead of attempting auto-detection."
        )
    argument_group.add_argument('--process_archives', '--process-archives',
        dest='process_archives', action='store_true', default=False, help=
        'Process file entries embedded within archive files, such as archive.tar and archive.zip. This can make processing significantly slower.'
        )
    argument_group.add_argument('--skip_compressed_streams',
        '--skip-compressed-streams', dest='process_compressed_streams',
        action='store_false', default=True, help=
        'Skip processing file content within compressed streams, such as syslog.gz and syslog.bz2.'
        )
