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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 _query_iterator(self, result, chunksize, columns, coerce_float=True, parse_dates=None):
 """Return generator through chunked result set."""


        while True:
            data = result.fetchmany(chunksize)
            if not data:
                break
            else:
                self.frame = DataFrame.from_records(
                    data, columns=columns, coerce_float=coerce_float)

                self._harmonize_columns(parse_dates=parse_dates)

                if self.index is not None:
                    self.frame.set_index(self.index, inplace=True)

                yield self.frame