syntax_data: {"ast_node_type":"variable","tokens":[{"end":45,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let ty = args.type_at(0);
context_before:                 &ty::Adt(adt_def, args) if tcx.is_lang_item(adt_def.did(), hir::LangItem::Pin) => {
context_after:                     let arg_ty = self.typeck_results.expr_ty(arg_expr);