syntax_data: {"ast_node_type":"variable","tokens":[{"end":34,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let r1 = match r0.kind() {
context_before:     fn fold_region(&mut self, r0: ty::Region<'tcx>) -> ty::Region<'tcx> {
context_after:             ty::ReVar(vid) => self