Status FromProto(const tensorflow::TensorProto& from);

  tensorflow::Tensor& Tensor() { return tensor_; }

 private:
  tensorflow::Tensor tensor_;
};

inline Tensor& TensorFromInterface(AbstractTensorInterface* tensor) {
  return down_cast<TensorInterface*>(tensor)->Tensor();
}

AbstractTensorInterface* TensorInterfaceFromTensor(const Tensor& src,