{"ast_node_type":"other","tokens":[{"end":51,"kind":"keyword","start":0,"text":"region_bound_pairs:"}]}
    region_bound_pairs: &'a RegionBoundPairs<'tcx>,
    user_type_annotations: &'a CanonicalUserTypeAnnotations<'tcx>,
    known_type_outlives_obligations: &'a [ty::PolyTypeOutlivesPredicate<'tcx>],