How to use the imgtool.version.decode_version function in imgtool

def sign(key, align, version, header_size, pad_header, slot_size, pad,
         max_sectors, overwrite_only, endian, encrypt, infile, outfile):
    img = image.Image(version=decode_version(version), header_size=header_size,
                      pad_header=pad_header, pad=pad, align=int(align),
                      slot_size=slot_size, max_sectors=max_sectors,
                      overwrite_only=overwrite_only, endian=endian)
    img.load(infile)
    key = load_key(key) if key else None
    enckey = load_key(encrypt) if encrypt else None
    if enckey:
        if not isinstance(enckey, (keys.RSA2048, keys.RSA2048Public)):
            raise Exception("Encryption only available with RSA")
        if key and not isinstance(key, (keys.RSA2048, keys.RSA2048Public)):
            raise Exception("Encryption with sign only available with RSA")
    img.create(key, enckey)
    img.save(outfile)

def sign(key, align, version, header_size, pad_header, slot_size, pad,
         max_sectors, overwrite_only, endian, encrypt, infile, outfile,
         dependencies, load_addr, hex_addr, erased_val):
    img = image.Image(version=decode_version(version), header_size=header_size,
                      pad_header=pad_header, pad=pad, align=int(align),
                      slot_size=slot_size, max_sectors=max_sectors,
                      overwrite_only=overwrite_only, endian=endian,
                      load_addr=load_addr, erased_val=erased_val)
    img.load(infile)
    key = load_key(key) if key else None
    enckey = load_key(encrypt) if encrypt else None
    if enckey and key:
        if ((isinstance(key, keys.ECDSA256P1) and
             not isinstance(enckey, keys.ECDSA256P1Public))
                or (isinstance(key, keys.RSA) and
                    not isinstance(enckey, keys.RSAPublic))):
            # FIXME
            raise Exception("Signing and encryption must use the same type of key")
    img.create(key, enckey, dependencies)
    img.save(outfile, hex_addr)

def validate_version(ctx, param, value):
    try:
        decode_version(value)
        return value
    except ValueError as e:
        raise click.BadParameter("{}".format(e))

def validate_version(ctx, param, value):
    try:
        decode_version(value)
        return value
    except ValueError as e:
        raise click.BadParameter("{}".format(e))

def get_dependencies(ctx, param, value):
    if value is not None:
        versions = []
        images = re.findall(r"\((\d+)", value)
        if len(images) == 0:
            raise click.BadParameter(
                "Image dependency format is invalid: {}".format(value))
        raw_versions = re.findall(r",\s*([0-9.+]+)\)", value)
        if len(images) != len(raw_versions):
            raise click.BadParameter(
                '''There's a mismatch between the number of dependency images
                and versions in: {}'''.format(value))
        for raw_version in raw_versions:
            try:
                versions.append(decode_version(raw_version))
            except ValueError as e:
                raise click.BadParameter("{}".format(e))
        dependencies = dict()
        dependencies[image.DEP_IMAGES_KEY] = images
        dependencies[image.DEP_VERSIONS_KEY] = versions
        return dependencies