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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 next(self):
 """ Return a new query with a modified `start_index`. Mainly used internally to paginate through results. """

        step = self.raw.get('max_results', 1000)
        start = self.raw.get('start_index', 1) + step
        self.raw['start_index'] = start
        return self