GraphErrorInjectionPass::enabled_ = false;
}

string VariableAddFunctionWithGraphError() {
  string signature = VariableAddFunctionSignature();
  // Replace the node 'read0' with 'read0_maybe_with_graph_error', so that the
  // error injecting pass can identify and introduce graph pass errors.
  signature = std::regex_replace(signature, std::regex("read0"),
                                 "read0_maybe_with_graph_error");

  if (TF_GetCode(status) != TF_OK) return;

  tensorflow::GradientDef gdef;
  gdef.set_function_name(func->record->fdef().signature().name());
  gdef.set_gradient_func(grad->record->fdef().signature().name());
  status->status = g->graph.AddGradientDef(std::move(gdef));
}

int TF_GraphNumFunctions(TF_Graph* g) {
  tensorflow::mutex_lock l(g->mu);

      return tensorflow::errors::InvalidArgument("Unsupported Type Codes: ",
                                                 dtype.code);
  }
}

// Wraps the deleter function of DLManagedTensor to match the function signature
// TFE_NewTensorHandleFromDeviceMemory.
void DeallocatorWrapperFunc(void* data, size_t len, void* dlmt_vptr) {
  TFE_CallDLManagedTensorDeleter(dlmt_vptr);
}

  std::vector<string> names;
  auto functions = graph_def.library().function();
  names.reserve(functions.size());
  for (const tensorflow::FunctionDef& func : functions) {
    names.push_back(func.signature().name());
  }
  std::sort(names.begin(), names.end());
  return names;
}

CSession::CSession(TF_Graph* graph, TF_Status* s, bool use_XLA) {
  TF_SessionOptions* opts = TF_NewSessionOptions();

    const std::string& filename, int64_t file_signature) {
  absl::MutexLock lock(&mu_);
  auto it = file_signature_map_.find(filename);
  if (it != file_signature_map_.end()) {
    if (it->second == file_signature) {
      return true;
    }
    // Remove the file from cache if the signatures don't match.
    RemoveFile_Locked(filename);
    it->second = file_signature;
    return false;
  }

      if (TF_GetCode(status) != TF_OK) return -1;
      if (!gcs_file->file_block_cache->ValidateAndUpdateFileSignature(
              path, stat.generation_number)) {
        TF_VLog(
            1,
            "File signature has been changed. Refreshing the cache. Path: %s",
            path.c_str());
      }
      read = gcs_file->file_block_cache->Read(path, offset, n, buffer, status);
    } else {

  // Second read. Hit cache.
  EXPECT_TRUE(cache.ValidateAndUpdateFileSignature(filename, 123));
  TF_EXPECT_OK(ReadCache(&cache, filename, 0, 16, &out));
  EXPECT_EQ(calls, 1);

  // Third read. File signatures are different.
  EXPECT_FALSE(cache.ValidateAndUpdateFileSignature(filename, 321));
  TF_EXPECT_OK(ReadCache(&cache, filename, 0, 16, &out));
  EXPECT_EQ(calls, 2);
}

TEST(RamFileBlockCacheTest, PassThrough) {