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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 _set_rowcount(self, query_results):
 """Set the rowcount from query results. Normally, this sets rowcount to the number of rows returned by the query, but if it was a DML statement, it sets rowcount to the number of modified rows. :type query_results: :class:`~google.cloud.bigquery.query._QueryResults` :param query_results: results of a query """

        total_rows = 0
        num_dml_affected_rows = query_results.num_dml_affected_rows

        if query_results.total_rows is not None and query_results.total_rows > 0:
            total_rows = query_results.total_rows
        if num_dml_affected_rows is not None and num_dml_affected_rows > 0:
            total_rows = num_dml_affected_rows
        self.rowcount = total_rows