return tsl::string("dummy_path");
  }

  // This is the part that would break the `CreateTmpDir` function because it
  // fails to provide a valid file system.
  absl::Status GetFileSystemForFile(const std::string& fname,
                                    tsl::FileSystem** result) override {
    return absl::InternalError("Broken file system");
  }

 private: