}

// Checks if one tensor type can refine another type for tf.While/
// tf.WhileRegion. If rank differs or static dimensions can be lost, the other
// type cannot be used for refinement.
bool CanWhileTypeBeRefinedWith(TensorType current_type,
                               TensorType potential_refined_type) {
  if (!current_type.hasRank()) return true;
  if (!potential_refined_type.hasRank()) return false;