{"ast_node_type":"impl","tokens":[{"end":97,"kind":"keyword","start":0,"text":"tcx.dcx().span_delayed_bug(tcx.def_span(impl_def_id),"}]}
        tcx.dcx().span_delayed_bug(tcx.def_span(impl_def_id), "default impl cannot be negative");
    if tcx.defaultness(impl_def_id).is_default() {
    }