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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 response_as_series(self):
 """ Return the response as a single series """

        assert len(self.symbols) == 1, 'expected single request'
        if self.response_type == 'frame':
            return self.response.ix[self.symbols[0]]
        else:
            return pandas.Series(self.response[self.symbols])