{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"fn"}]}
    fn successors(&self, bb: Self::Node) -> impl Iterator<Item = Self::Node> {
impl<'a, 'tcx> graph::Successors for CoverageRelevantSubgraph<'a, 'tcx> {
        self.coverage_successors(bb).into_iter()