{"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"//"}]}
        // Perf testing has found that this check is slightly faster than
    fn fold_with<F: TypeFolder<TyCtxt<'tcx>>>(self, folder: &mut F) -> Self {
        // folding and re-interning an empty `ExternalConstraintsData`.