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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 execute(self, ignore_cache=False, raise_on_error=True):
 """ Execute the multi search request and return a list of search results. """

        if ignore_cache or not hasattr(self, '_response'):
            es = connections.get_connection(self._using)

            responses = es.msearch(
                index=self._index,
                body=self.to_dict(),
                **self._params
            )

            out = []
            for s, r in zip(self._searches, responses['responses']):
                if r.get('error', False):
                    if raise_on_error:
                        raise TransportError('N/A', r['error']['type'], r['error'])
                    r = None
                else:
                    r = Response(s, r)
                out.append(r)

            self._response = out

        return self._response