Function region_known_to_outlive

fn region_known_to_outlive<'tcx>(
    tcx: TyCtxt<'tcx>,
    id: LocalDefId,
    param_env: ParamEnv<'tcx>,
    wf_tys: &FxIndexSet<Ty<'tcx>>,
    region_a: Region<'tcx>,
    region_b: Region<'tcx>,
) -> bool

Given a known param_env and a set of well formed types, can we prove that region_a outlives region_b