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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 serialize_rfc(attr, **kwargs):
 """Serialize Datetime object into RFC-1123 formatted string. :param Datetime attr: Object to be serialized. :rtype: str :raises: TypeError if format invalid. """

        try:
            if not attr.tzinfo:
                _LOGGER.warning(
                    "Datetime with no tzinfo will be considered UTC.")
            utc = attr.utctimetuple()
        except AttributeError:
            raise TypeError("RFC1123 object must be valid Datetime object.")

        return "{}, {:02} {} {:04} {:02}:{:02}:{:02} GMT".format(
            Serializer.days[utc.tm_wday], utc.tm_mday,
            Serializer.months[utc.tm_mon], utc.tm_year,
            utc.tm_hour, utc.tm_min, utc.tm_sec)