def METHOD_NAME(subparsers):
    """ Create the parser for the "sync" command. """
    sync_parser = subparsers.add_parser('sync',
                                       help='sync channels')
    sync_parser.add_argument(
        'sync_target',
        choices=['channel', 'channels'])
    sync_parser.add_argument(
        'target',
        nargs='*',
        help='element to sync')
    sync_parser.add_argument(
        '--with-children', action='store_true', dest='with_children',
        help='Sync all child channels as well')