{"ast_node_type":"variable","tokens":[{"end":68,"kind":"keyword","start":0,"text":"let"}]}
                    let field = variant.fields.iter().find(|field| {
                    let typing_env = ty::TypingEnv::post_analysis(self.tcx, variant.def_id);
                        let ty = self.tcx.type_of(field.did).instantiate_identity();