{"ast_node_type":"function","tokens":[{"end":56,"kind":"keyword","start":0,"text":"fn"}]}
    fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
impl<'tcx> Visitor<'tcx> for LocalCollector {
        if let hir::PatKind::Binding(_, hir_id, ..) = pat.kind {