syntax_data: {"ast_node_type":"variable","tokens":[{"end":55,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let types = match tcx.as_lang_item(trait_def) {
context_before:         );
context_after:             Some(LangItem::Sized) => self.sizedness_conditions(self_ty, SizedTraitKind::Sized),