}

}  // namespace tf_random_access_file

// SECTION 2. Implementation for `TF_WritableFile`
// ----------------------------------------------------------------------------
namespace tf_writable_file {

typedef struct PosixFile {
  const char* filename;
  FILE* handle;
} PosixFile;

static void Cleanup(TF_WritableFile* file) {
  auto posix_file = static_cast<PosixFile*>(file->plugin_file);

  std::unique_ptr<WritableFile> new_file;
  Status status = env_->NewWritableFile(filepath, &new_file);
  EXPECT_PRED2(UnimplementedOrReturnsCode, status, Code::OK);
}

TEST_P(ModularFileSystemTest, TestCreateFileNonExisting) {
  const std::string filepath = GetURIForPath("dir_not_found/a_file");
  std::unique_ptr<WritableFile> new_file;

  Status NewWritableFile(const std::string& fname, TransactionToken* token,
                         std::unique_ptr<WritableFile>* result) override;
  Status NewAppendableFile(const std::string& fname, TransactionToken* token,
                           std::unique_ptr<WritableFile>* result) override;
  Status NewReadOnlyMemoryRegionFromFile(
      const std::string& fname, TransactionToken* token,

namespace tf_random_access_file {

// TODO(b/139060984): Implement later

}  // namespace tf_random_access_file

// SECTION 2. Implementation for `TF_WritableFile`
// ----------------------------------------------------------------------------
namespace tf_writable_file {

// TODO(b/139060984): Implement later

}  // namespace tf_writable_file

    std::unique_ptr<WritableFile>* result) {
  if (ops_->new_writable_file == nullptr)
    return errors::Unimplemented(tensorflow::strings::StrCat(
        "Filesystem for ", fname, " does not support NewWritableFile()"));

  UniquePtrTo_TF_Status plugin_status(TF_NewStatus(), TF_DeleteStatus);
  auto file = std::make_unique<TF_WritableFile>();
  std::string translated_name = TranslateName(fname);

      return;
    }
    *offset = static_cast<int64_t>(metadata->size());
    TF_SetStatus(status, TF_OK, "");
  }
}

void Cleanup(TF_WritableFile* file) {
  auto gcs_file = static_cast<GCSFile*>(file->plugin_file);
  delete gcs_file;
}

void Append(const TF_WritableFile* file, const char* buffer, size_t n,
            TF_Status* status) {
  auto gcs_file = static_cast<GCSFile*>(file->plugin_file);

/// to initialize it as `nullptr`.

typedef struct TF_RandomAccessFile {
  void* plugin_file;
} TF_RandomAccessFile;

typedef struct TF_WritableFile {
  void* plugin_file;
} TF_WritableFile;

typedef struct TF_ReadOnlyMemoryRegion {
  void* plugin_memory_region;
} TF_ReadOnlyMemoryRegion;

typedef struct TF_Filesystem {
  void* plugin_filesystem;
} TF_Filesystem;