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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 target(self, hosts):
 """Temporarily retarget the client for one call. This is useful when having to deal with a subset of hosts for one call. """

        if self.__is_retargeted:
            raise TypeError('Cannot use target more than once.')
        rv = FanoutClient(hosts, connection_pool=self.connection_pool,
                          max_concurrency=self._max_concurrency)
        rv._cb_poll = self._cb_poll
        rv.__is_retargeted = True
        return rv