def METHOD_NAME(anchor=undefined, package=undefined):
    if package is not undefined:
        if anchor is not undefined:
            return func(anchor, package)
        warnings.warn(
            "First parameter to files is renamed to 'anchor'",
            DeprecationWarning,
            stacklevel=2,
        )
        return func(package)
    elif anchor is undefined:
        return func()
    return func(anchor)