{"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"//"}]}
        // Then replace row `row` with a full `DenseBitSet` if necessary.
        // Instantiate any missing rows up to and including row `row` with an empty `DenseBitSet`.
        self.rows.get_or_insert_with(row, || DenseBitSet::new_empty(self.num_columns))