const size_t size = 256;
  std::vector<char> buf;
  buf.reserve(size);
  for (int i = 0; i < size; i++) {
    buf.push_back(i);
  }
  // The fetcher just fetches slices of the buffer.
  auto fetcher = [&buf](const string& filename, size_t offset, size_t n,
                        char* buffer, TF_Status* status) -> int64_t {
    int64_t bytes_transferred;
    if (offset < buf.size()) {

  auto* cell2 = TFE_MonitoringGetCellStringGauge2(gauge2, "foo", "bar");
  TFE_MonitoringStringGaugeCellSet(cell2, "str");
  auto* buf = new TF_Buffer;
  TFE_MonitoringStringGaugeCellValue(cell2, buf);
  string data(static_cast<const char*>(buf->data), buf->length);
  TF_DeleteBuffer(buf);
  EXPECT_EQ(data, "str");
  TFE_MonitoringDeleteStringGauge2(gauge2);
  TF_DeleteStatus(status);
}

  OwnedTFStatus c_status(TF_NewStatus());
  OwnedTFBuffer graph_buf(TF_NewBuffer());
  OwnedTFBuffer optimized_graph_buf(TF_NewBuffer());
  TF_RETURN_IF_ERROR(MessageToBuffer(item.graph, graph_buf.get()));

  optimizer_.optimize_func(c_optimizer_, graph_buf.get(),
                           reinterpret_cast<const TF_GrapplerItem*>(&item),
                           optimized_graph_buf.get(), c_status.get());

}

const void TFE_MonitoringStringGaugeCellValue(
    TFE_MonitoringStringGaugeCell* cell, TF_Buffer* buf) {
  tensorflow::string value = cell->cell.value();
  void* data = tensorflow::port::Malloc(value.length());
  value.copy(static_cast<char*>(data), value.length(), 0);
  buf->data = data;
  buf->length = value.length();
  buf->data_deallocator = [](void* data, size_t length) {
    tensorflow::port::Free(data);
  };
}

  for (size_t i = 0; i < values.size(); i++) {
    memset(&option_values[i], 0, sizeof(option_values[i]));
    option_values[i].buffer_val.buf = const_cast<char*>(values[i].c_str());
    option_values[i].buffer_val.buf_length = values[i].size();
  }
  option_value.values = &option_values[0];
  option.value = &option_value;
  UniquePtrTo_TF_Status plugin_status(TF_NewStatus(), TF_DeleteStatus);

// Serialize `attrs` as a tensorflow::NameAttrList protocol buffer (into `buf`),
// containing the op name and a map of its attributes.
TF_CAPI_EXPORT extern void TFE_OpAttrsSerialize(const TFE_OpAttrs* attrs,
                                                TF_Buffer* buf,
                                                TF_Status* status);

  Status s = MessageToBuffer(g_def, g_buf);
  TF_ASSERT_OK(s);
  TF_FunctionLibraryDefinition* func =
      TF_NewFunctionLibraryDefinition(g_buf, status);

  TF_LookUpOpDef(func, "Add", op_buf, status);
  string actual_string(reinterpret_cast<const char*>(op_buf->data),
                       op_buf->length);
  ASSERT_EQ(TF_OK, TF_GetCode(status));

  const OpDef* expected_op_def;

  // the device?
  TF_ManagedBuffer* buf =
      new TF_ManagedBuffer(data, len, deallocator, deallocator_arg,
                           /*owns_memory=*/false);

  tensorflow::Tensor t(static_cast<tensorflow::DataType>(dtype),
                       tensorflow::TensorShape(dimvec), buf);
  buf->Unref();
  return tensorflow::wrap(tensorflow::TensorHandle::CreateLocalHandle(

typedef struct TF_FunctionLibraryDefinition TF_FunctionLibraryDefinition;

// Create NewFunctionLibraryDefinition.
TF_CAPI_EXPORT extern TF_FunctionLibraryDefinition*
TF_NewFunctionLibraryDefinition(const TF_Buffer* graph_buf, TF_Status* status);

// Delete NewFunctionLibraryDefinition.
TF_CAPI_EXPORT extern void TF_DeleteFunctionLibraryDefinition(
    TF_FunctionLibraryDefinition* fn_lib);

    VLOG(1) << "Adding func to graph: " << fdef_to_load.DebugString();
    std::vector<char> binary_proto_buf(fdef_to_load.ByteSizeLong());
    fdef_to_load.SerializeToArray(binary_proto_buf.data(),
                                  binary_proto_buf.size());
    TF_Function* func = TF_FunctionImportFunctionDef(
        binary_proto_buf.data(), binary_proto_buf.size(), status);
    if (!status->status.ok()) return {};