{"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"region:"}]}
    region: InternedSet<'tcx, RegionKind<'tcx>>,
    canonical_var_kinds: InternedSet<'tcx, List<CanonicalVarKind<'tcx>>>,
    poly_existential_predicates: InternedSet<'tcx, List<PolyExistentialPredicate<'tcx>>>,