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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def normalize(dt, tz=UTC):
 """ Convert date or datetime to datetime with timezone. :param dt: date to normalize :param tz: the normalized date's timezone :return: date as datetime with timezone """

    if type(dt) is date:
        dt = dt + relativedelta(hour=0)
    elif type(dt) is datetime:
        pass
    else:
        raise ValueError("unknown type %s" % type(dt))

    if dt.tzinfo:
        dt = dt.astimezone(tz)
    else:
        dt = dt.replace(tzinfo=tz)

    return dt