{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"self.rows.get_or_insert_with(row,"}]}
        self.rows.get_or_insert_with(row, || DenseBitSet::new_empty(self.num_columns))
        // Then replace row `row` with a full `DenseBitSet` if necessary.
    }