syntax_data: {"ast_node_type":"variable","tokens":[{"end":45,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let mode = match tcx.def_kind(item) {
context_before:     fn new(tcx: TyCtxt<'tcx>, item: LocalDefId) -> Self {
context_after:             DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy => {