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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 ms_to_datetime(ms):
 """ Converts a millisecond accuracy timestamp to a datetime """

    dt = datetime.datetime.utcfromtimestamp(ms / 1000)
    return dt.replace(microsecond=(ms % 1000) * 1000).replace(tzinfo=pytz.utc)