{"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":".impl_trait_mode(ImplTraitLoweringMode::Opaque);"}]}
                            .impl_trait_mode(ImplTraitLoweringMode::Opaque);
                        ctx.type_param_mode(ParamLoweringMode::Placeholder)
                        ctx.lower_ty(return_ty)