{"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"assert!(read.index()"}]}
        assert!(read.index() < self.num_rows && write.index() < self.num_rows);
    pub fn union_rows(&mut self, read: R, write: R) -> bool {
        let (read_start, read_end) = self.range(read);