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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 define_cyclic_can_msg(self, channel, can_msg=None):
 """ Defines a list of CAN messages for automatic transmission. :param int channel: CAN channel, to be used (:data:`Channel.CHANNEL_CH0` or :data:`Channel.CHANNEL_CH1`). :param list(CanMsg) can_msg: List of CAN messages (up to 16, see structure :class:`CanMsg`), or None to delete an older list. """

        if can_msg is not None:
            c_can_msg = (CanMsg * len(can_msg))(*can_msg)
            c_count = DWORD(len(can_msg))
        else:
            c_can_msg = CanMsg()
            c_count = 0
        UcanDefineCyclicCanMsg(self._handle, channel, c_can_msg, c_count)