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

        assert hostport, "hostport is required"
        assert isinstance(hostport, basestring), "hostport must be a string"

        if hostport not in self._peers:
            self._add(hostport)

        return self._peers[hostport]