{"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"CanonicalizeMode::Input(_)"}]}
                CanonicalizeMode::Input(_) => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
                // We canonicalize placeholder regions as existentials in query inputs.
                CanonicalizeMode::Response { max_input_universe } => {