code: def __iter__(self) -> Iterator[TensorDict]:
      yield from self._outputs
  
imports: from typing import Iterator, List
  import torch
  import pytest
  import json
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.common import Params
  from allennlp.common.util import sanitize
  from allennlp.data.data_loaders import TensorDict
  from allennlp.evaluation import Serializer
  from allennlp.evaluation.serializers import SimpleSerializer
label_desc: Use image node_id 2 for calling the DummyDataLoader obj's underlying member method code with example usage: obj.__iter__() without return types