syntax_data: {"ast_node_type":"variable","tokens":[{"end":53,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let self_ty = match args.kind() {
context_before:                     let sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), args.sig());
context_after:                         ty::ClosureKind::Fn => {