{"ast_node_type":"function","tokens":[{"end":57,"kind":"keyword","start":0,"text":"fn"}]}
    fn union(&mut self, other: &DenseBitSet<T>) -> bool {
impl<T: Idx> BitRelations<DenseBitSet<T>> for DenseBitSet<T> {
        assert_eq!(self.domain_size, other.domain_size);