pub(crate) trait ExistentialTraitRefHelpers<'tcx> {
    // Required method
    fn new_from_args(
        &self,
        trait_def_id: DefId,
        args: GenericArgsRef<'tcx>,
    ) -> ExistentialTraitRef<'tcx>;
}pub(crate) trait ExistentialTraitRefHelpers<'tcx> {
    // Required method
    fn new_from_args(
        &self,
        trait_def_id: DefId,
        args: GenericArgsRef<'tcx>,
    ) -> ExistentialTraitRef<'tcx>;
}