Invoke the optional get_requires_for_build_wheel hook

    Returns [] if the hook is not defined.

def get_requires_for_build_sdist(config_settings):
    """Invoke the optional get_requires_for_build_wheel hook

    Returns [] if the hook is not defined.
    """
    backend = _build_backend()
    try:
        hook = backend.get_requires_for_build_sdist
    except AttributeError:
        return []
    else:
        return hook(config_settings)