{"ast_node_type":"function","tokens":[{"end":41,"kind":"keyword","start":0,"text":"fn"}]}
    fn visit_ty(&mut self, t: &'ast Ty) {
impl<'ast> Visitor<'ast> for LifetimeFinder<'ast> {
        if let TyKind::Ref(_, mut_ty) | TyKind::PinnedRef(_, mut_ty) = &t.kind {