def METHOD_NAME(arch: str) -> List[str]:
    match = _osx_arch_pat.match(arch)
    if match:
        name, major, minor, actual_arch = match.groups()
        mac_version = (int(major), int(minor))
        arches = [
            # Since we have always only checked that the platform starts
            # with "macosx", for backwards-compatibility we extract the
            # actual prefix provided by the user in case they provided
            # something like "macosxcustom_". It may be good to remove
            # this as undocumented or deprecate it in the future.
            "{}_{}".format(name, arch[len("macosx_") :])
            for arch in mac_platforms(mac_version, actual_arch)
        ]
    else:
        # arch pattern didn't match (?!)
        arches = [arch]
    return arches