root_dir_ = tensorflow::strings::StrCat(GetParam(), "://", cloud_path_,
                                              root_dir_);
    }
    env_ = Env::Default();
  }

  void SetUp() override {
    FileSystem* fs = nullptr;
    Status s = env_->GetFileSystemForFile(root_dir_, &fs);
    if (fs == nullptr || !s.ok())
      GTEST_SKIP() << "No filesystem registered: " << s;

    s = fs->CreateDir(root_dir_);

                  server_def_0, tensorflow::Env::Default(), &worker_server1)
                  .ok());
  ASSERT_TRUE(worker_server1->Start().ok());
  server_def_0.set_task_index(2);
  std::unique_ptr<tensorflow::GrpcServer> worker_server2;
  ASSERT_TRUE(tensorflow::GrpcServer::Create(
                  server_def_0, tensorflow::Env::Default(), &worker_server2)
                  .ok());