return it->getFirst().getType();
  };
  auto arg_buffer_size_is_fixed = [&](int64_t index) {
    return (*buffer_to_size)[while_op.getOperand(index)].fixed;
  };
  OpBuilder builder(while_op);
  ModifyFunctionSignature(body, cutil::GetSizeType(builder), &body_map,
                          find_arg_tensor_list_type, arg_buffer_size_is_fixed);
  if (failed(DecomposeTensorListOpsInternal(