{"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":")"}]}
    ) -> Option<ty::EarlyBinder<'tcx, Ty<'tcx>>> {
        key: (DefId, SizedTraitKind)
        desc { |tcx| "computing the sizedness constraint for `{}`", tcx.def_path_str(key.0) }