def METHOD_NAME(instance_type: str,
                    use_spot: bool = False,
                    region: Optional[str] = None,
                    zone: Optional[str] = None) -> float:
    """Returns the cost, or the cheapest cost among all zones for spot."""
    assert not use_spot, 'Lambda Cloud does not support spot.'
    if zone is not None:
        with ux_utils.print_exception_no_traceback():
            raise ValueError('Lambda Cloud does not support zones.')
    return common.get_hourly_cost_impl(_df, instance_type, use_spot, region,
                                       zone)