// Create two contexts.
  int32_t init_timeout_in_ms = 300000;
  TFE_Context* ctx_0 =
      CreateContext(serialized_server_def_0,
                    /*isolate_session_state=*/false, init_timeout_in_ms);
  TFE_Context* ctx_1 =
      CreateContext(serialized_server_def_1,
                    /*isolate_session_state=*/false, init_timeout_in_ms);

  // Remote device on `worker2`.

  TF_RETURN_IF_ERROR(
      env->GetSymbolFromLibrary(dso_handle, "TF_InitGraph", &dso_symbol));

  // Step 2: Call `TF_InitPlugin`
  auto init_fn = reinterpret_cast<TFInitGraphPluginFn>(dso_symbol);
  return InitGraphPlugin(init_fn);
}

absl::Status InitGraphPlugin(TFInitGraphPluginFn init_fn) {
  TP_OptimizerRegistrationParams params{
      TP_OPTIMIZER_REGISTRATION_PARAMS_STRUCT_SIZE};

// or removed during the graph transformation. This includes feed and fetch
// nodes, keep_ops, init_ops. Fills in `num_values` and `storage_size`, they
// will be used in `TF_GetNodesToPreserveList`.
TF_CAPI_EXPORT extern void TF_GetNodesToPreserveListSize(
    const TF_GrapplerItem* item, int* num_values, size_t* storage_size,
    TF_Status* status);

  if (ops == nullptr)
    return errors::FailedPrecondition(
        "Trying to register filesystem without operations");

  if (ops->init == nullptr)
    return errors::FailedPrecondition(
        "Trying to register filesystem without `init` operation");

  if (ops->cleanup == nullptr)
    return errors::FailedPrecondition(
        "Trying to register filesystem without `cleanup` operation");

TF_CAPI_EXPORT extern void TFE_ContextSetServerDefWithTimeout(
    TFE_Context* ctx, int keep_alive_secs, const void* proto, size_t proto_len,
    int64_t init_timeout_in_ms, TF_Status* status,
    bool clear_existing_contexts) {
  TFE_ContextSetServerDefWithTimeoutAndRetries(
      ctx, keep_alive_secs, proto, proto_len, init_timeout_in_ms,
      /*retries=*/0, status, clear_existing_contexts);
}

    params->device_type = "Device1";
  };

  TF_ASSERT_OK(InitGraphPlugin(plugin_init_0));
  TF_ASSERT_OK(InitGraphPlugin(plugin_init_1));
  ASSERT_EQ(PluginGraphOptimizerRegistry::CreateOptimizers(
                std::set<string>{"Device0", "Device1"})
                .size(),
            2);
}

TEST(Grappler, DeviceTypeNotSet) {
  auto plugin_init = [](TP_OptimizerRegistrationParams* const params,

  ops->filesystem_ops = static_cast<TF_FilesystemOps*>(
      plugin_memory_allocate(TF_FILESYSTEM_OPS_SIZE));
  ops->filesystem_ops->init = tf_posix_filesystem::Init;
  ops->filesystem_ops->cleanup = tf_posix_filesystem::Cleanup;
  ops->filesystem_ops->new_random_access_file =
      tf_posix_filesystem::NewRandomAccessFile;

    TFE_Context* ctx, int keep_alive_secs, const void* proto, size_t proto_len,
    int64_t init_timeout_in_ms, TF_Status* status);

// This API is for experimental usage and may be subject to change.
TF_CAPI_EXPORT extern void TFE_ContextSetServerDefWithTimeout(
    TFE_Context* ctx, int keep_alive_secs, const void* proto, size_t proto_len,
    int64_t init_timeout_in_ms, TF_Status* status,

  }
  return server_def;
}

tensorflow::ServerDef GetServerDef(int num_tasks) {
  return GetServerDef("localhost", num_tasks);
}

tensorflow::ServerDef GetMultiClientServerDef(const std::string& job_name,
                                              int num_tasks,
                                              int num_virtual_gpus) {
  tensorflow::ServerDef server_def;
  server_def.set_protocol("grpc");

  // fill the cache, and the loop with i = 1 should be all cache hits. The
  // fetcher checks that it is called once and only once for each offset (to
  // fetch the corresponding block).
  for (int i = 0; i < 2; i++) {
    for (int j = 0; j < block_count; j++) {
      TF_EXPECT_OK(ReadCache(&cache, "", block_size * j, block_size, &out));
    }
  }
}

TEST(RamFileBlockCacheTest, OutOfRange) {