def METHOD_NAME():
    args = parse_arguments(sys.argv[1:])
    fn_in = os.path.abspath(os.path.realpath(os.path.expanduser(args.fn_in)))
    if not os.path.isfile(fn_in):
        raise IOError('Could not find file: {0}'.format(args.fn_in))
    m2m_dir = os.path.abspath(os.path.realpath(os.path.expanduser(args.m2mpath)))
    if not os.path.isdir(m2m_dir):
        raise IOError('Could not find directory: {0}'.format(args.m2mpath))
    fn_out = os.path.abspath(os.path.realpath(os.path.expanduser(args.out)))
    if os.path.splitext(fn_out)[1] == '':
        fn_out += '.nii.gz'
    if args.r is not None:
        reference = os.path.abspath(os.path.realpath(os.path.expanduser(args.r)))
    else:
        reference = None
    if args.mask is not None:
        mask = os.path.abspath(os.path.realpath(os.path.expanduser(args.mask)))
    else:
        mask = None
    transformations.warp_volume(
        fn_in, m2m_dir, fn_out,
        transformation_direction='mni2subject',
        transformation_type=args.t,
        reference=reference,
        mask=mask,
        order=args.int_order)