int64_t FlattenedOutDimensionSize() const {
    if (ShapedType::isDynamicShape(out_dimensions_.sizes)) {
      return ShapedType::kDynamic;
    }
    return std::accumulate(out_dimensions_.sizes.begin(),
                           out_dimensions_.sizes.end(), 1,
                           std::multiplies<int64_t>());
  }

 private:
  DimensionVector batch_dimensions_;

  SmallVector<int64_t> output_shape;
  ArrayRef<int64_t> input_shape = input_tensor.getType().getShape();
  auto attr_iter = perm_tensor.getValues<IntegerAttr>();
  const int num_dimensions = input_tensor.getType().getRank();
  for (int i = 0; i < num_dimensions; ++i) {
    perms.push_back(attr_iter[i].getInt());
    output_shape.push_back(input_shape[perms[i]]);
  }