code: def configure(self, *args, **kwargs):
      ds = ray.data.range(10)
      return [
          {"train": ds.iterator()},
          {"train": ds.iterator()},
      ]
  
imports: from typing import Optional
  import random
  import pytest
  from unittest.mock import MagicMock
  import ray
  from ray import train
  from ray.train import DataConfig, ScalingConfig
  from ray.data import DataIterator
  from ray.train.data_parallel_trainer import DataParallelTrainer
  from ray.data._internal.execution.interfaces.execution_options import ExecutionOptions
  from ray.tests.conftest import *
label_desc: Use image node_id 2 for calling the CustomConfig obj's underlying member method code with example usage: obj.configure() and returns: list