{"ast_node_type":"variable","tokens":[{"end":82,"kind":"keyword","start":0,"text":"let"}]}
        let hir::ImplItemKind::Fn(_sig, body_id) = impl_item.kind else { return };
        let Some(default_def_id) = cx.tcx.get_diagnostic_item(sym::Default) else { return };
        let assoc = cx.tcx.associated_item(impl_item.owner_id);