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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 pre_dissect(self, s):
 """ Check that the payload is long enough to build a NTP packet. """

        length = len(s)
        if length < _NTP_PACKET_MIN_SIZE:
            err = " ({}".format(length) + " is < _NTP_PACKET_MIN_SIZE "
            err += "({})).".format(_NTP_PACKET_MIN_SIZE)
            raise _NTPInvalidDataException(err)
        return s