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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 pop_aggregations_params(self):
 """ Pop and return aggregation params from query string params. Aggregation params are expected to be prefixed(nested under) by any of `self._aggregations_keys`. """

        from nefertari.view import BaseView
        self._query_params = BaseView.convert_dotted(self.view._query_params)

        for key in self._aggregations_keys:
            if key in self._query_params:
                return self._query_params.pop(key)
        else:
            raise KeyError('Missing aggregation params')