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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 revoke_lease(self, lease_id):
 """ Revoke a lease. :param lease_id: ID of the lease to revoke. """

        lease_revoke_request = etcdrpc.LeaseRevokeRequest(ID=lease_id)
        self.leasestub.LeaseRevoke(
            lease_revoke_request,
            self.timeout,
            credentials=self.call_credentials,
            metadata=self.metadata
        )