def add_pull_parser(sub_parser):
    """
    Adds a sub-parser for the "pull" sub-command to the parser provided.

    :param sub_parser: the parser to add to
    :type sub_parser: <class 'argparse.ArgumentParser'>
    """
    pull_parser = sub_parser.add_parser('pull', help='Pull file from remote')
    pull_parser.add_argument('remote', help='remote to pull')
    pull_parser.add_argument('-k', '--key', help=
        'key of file to pull (from .surround/config.yaml)')
