rhs_element_type_with_subtype.GetSubtypes().size() == 1) {
    auto lhs_element_type_with_subtype =
        mlir::dyn_cast<TF::TensorFlowTypeWithSubtype>(lhs_element_type);
    TensorType subtype;
    if (!lhs_element_type_with_subtype) {
      DCOMMENT(
          "Unexpected inferred `TensorFlowTypeWithSubtype` when original "
          "result isn't");
    } else if (lhs_element_type_with_subtype.GetSubtypes().size() > 1) {

  supported_ops->insert(allowlist_ops.begin(), allowlist_ops.end());
}

bool IsStringType(Type type) {
  if (mlir::isa<mlir::TF::StringType>(type)) return true;

  auto sub_type = mlir::dyn_cast<mlir::TF::TensorFlowTypeWithSubtype>(type);
  if (!sub_type) return false;

  bool has_string = llvm::any_of(sub_type.GetSubtypes(), [](TensorType type) {
    return mlir::isa<mlir::TF::StringType>(type.getElementType());
  });