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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 set_epoch(self, epoch):
 """Set the GPS epoch """

        if epoch is None:
            self._epoch = None
            return
        if isinstance(epoch, (Number, Decimal)):
            self._epoch = float(epoch)
        else:
            self._epoch = float(to_gps(epoch))