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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 _round_half_hour(record):
 """ Round a time DOWN to half nearest half-hour. """

    k = record.datetime + timedelta(minutes=-(record.datetime.minute % 30))
    return datetime(k.year, k.month, k.day, k.hour, k.minute, 0)