int64 DenseTensorColumn<int64>::Feature(int64 batch, int64 n,
                                        bool strong_hash) const {
  if (DT_STRING == tensor_.dtype())
    return Fingerprint64(tensor_.matrix<tstring>()(batch, n));
  return tensor_.matrix<int64>()(batch, n);
}
int64 DenseTensorColumn<int64>::Feature(int64 batch, int64 n,
                                        bool strong_hash) const {
  if (DT_STRING == tensor_.dtype())
    return Fingerprint64(tensor_.matrix<tstring>()(batch, n));
  return tensor_.matrix<int64>()(batch, n);
}