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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 _get_persistent_mpe_dir(self):
 """ get persistent storage for mpe """

        mpe_address      = self.get_mpe_address().lower()
        registry_address = self.get_registry_address().lower()
        return Path.home().joinpath(".snet", "mpe_client", "%s_%s"%(mpe_address, registry_address))