{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"CanonicalVarKind::Region(ty::UniverseIndex::ROOT)"}]}
                    CanonicalVarKind::Region(ty::UniverseIndex::ROOT)
                CanonicalizeMode::Input(CanonicalizeInputKind::Predicate { .. }) => {
                }