{"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"assert!(matches!(x.ret_activity,"}]}
                    assert!(matches!(x.ret_activity, DiffActivity::None));
                    d_decl.output = FnRetTy::Ty(ty.clone());
                    // this won't be used below, so any type would be fine.