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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 replace_lun(self, *lun_list):
 """Replaces the exiting LUNs to lun_list."""

        lun_add = self._prepare_luns_add(lun_list)
        lun_remove = self._prepare_luns_remove(lun_list, False)
        return self.modify(lun_add=lun_add, lun_remove=lun_remove)