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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 using(self, client):
 """ Associate the search request with an elasticsearch client. A fresh copy will be returned with current instance remaining unchanged. :arg client: an instance of ``elasticsearch.Elasticsearch`` to use or an alias to look up in ``elasticsearch_dsl.connections`` """

        s = self._clone()
        s._using = client
        return s