def _serializeExclude_eval(parentUnit, priv):
    """
    Always decide not to serialize obj

    :param priv: private data for this function first unit of this class
    :return: tuple (do serialize this object, next priv, replacement unit)
    """

    # do not use this :class:`hwt.synthesizer.unit.Unit` instance and do not use any prelacement
    # (usefull when the :class:`hwt.synthesizer.unit.Unit` instance is a placeholder for something
    #  which already exists in hdl word)
    if priv is None:
        priv = parentUnit
        return False, priv, None
    else:
        return False, priv, priv