def METHOD_NAME(
    definition: "LabwareDefinition",
    length: float,
    cal_status: typing.Optional[
        typing.Union[local_types.CalibrationStatus, v1.CalibrationStatus]
    ] = None,
) -> typing.Dict[str, v1.TipLengthModel]:
    """
    Function to correctly format tip length data.
    :param definition: full labware definition
    :param length: the tip length to save
    """
    labware_hash = helpers.hash_labware_def(definition)
    labware_uri = helpers.uri_from_definition(definition)
    if isinstance(cal_status, local_types.CalibrationStatus):
        cal_status_model = v1.CalibrationStatus(**asdict(cal_status))
    elif isinstance(cal_status, v1.CalibrationStatus):
        cal_status_model = cal_status
    else:
        cal_status_model = v1.CalibrationStatus()
    tip_length_data = v1.TipLengthModel(
        tipLength=length,
        lastModified=utc_now(),
        source=local_types.SourceType.user,
        status=cal_status_model,
        uri=labware_uri,
    )
    data = {labware_hash: tip_length_data}
    return data