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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_isolated(self, hostport):
 """Get a Peer for the given destination for a request. A new Peer is added and returned if one does not already exist for the given host-port. Otherwise, the existing Peer is returned. **NOTE** new peers will not be added to the peer heap. """

        assert hostport, "hostport is required"
        if hostport not in self._peers:
            # Add a peer directly from a hostport, do NOT add it to the peer
            # heap
            peer = self.peer_class(
                tchannel=self.tchannel,
                hostport=hostport,
            )
            self._peers[peer.hostport] = peer

        return self._peers[hostport]