std::unique_ptr<TensorSliceReader::VarToShapeMap> var_to_shape_map_;
  std::unique_ptr<TensorSliceReader::VarToDataTypeMap> var_to_data_type_map_;

  CheckpointReader(const CheckpointReader&) = delete;
  void operator=(const CheckpointReader&) = delete;
};

}  // namespace checkpoint
}  // namespace tensorflow

const TensorSliceReader::VarToDataTypeMap&
CheckpointReader::GetVariableToDataTypeMap() const {
  CHECK(var_to_data_type_map_);
  return *var_to_data_type_map_;
}

const string CheckpointReader::DebugString() const {
  if (reader_ != nullptr) return reader_->DebugString();
  return v2_reader_->DebugString();
}

void CheckpointReader::GetTensor(
    const string& name, std::unique_ptr<tensorflow::Tensor>* out_tensor,