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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 targetLow(self):
 """Return the low byte of the target address field. Used in All-Link Cleanup messages. """

        low_byte = None
        if self.target is not None and self._messageFlags.isBroadcast:
            low_byte = self.target.bytes[0]
        return low_byte