});
  for (const auto& signature_def : signature_def_sorted) {
    uint64_t signature_def_pair_hash =
        FingerprintCat64(Fingerprint64(signature_def.first),
                         Fingerprint64(SerializeProto(signature_def.second)));
    signature_def_hash =
        FingerprintCat64(signature_def_hash, signature_def_pair_hash);
    SignatureDef signature_def_val = signature_def.second;
    TF_ASSIGN_OR_RETURN(

    result_hash =
        FingerprintCat64(result_hash, tensorflow::Fingerprint64(item.first));
    std::string signature_def_serialized;
    {
      StringOutputStream stream(&signature_def_serialized);
      CodedOutputStream output(&stream);
      output.SetSerializationDeterministic(true);
      item.second.SerializeToCodedStream(&output);
    }
    result_hash = FingerprintCat64(

      orig_op->MutableAttrs()->CacheKey(orig_op->DeviceName());
  // Include soft placement policy in cache key since the placement strategy
  // can change and thus affect which kernel is picked.
  auto x = FingerprintCat64(cache_key.high64, cache_key.low64);
  std::string fname =
      absl::StrCat("_expanded_", ndef.name(), "_", std::to_string(x));
  if (!ctx.FindFunctionByName(fname)) {