code: def test_simple_postprocessor_call(
      self, batch, output_dict, postprocess_func
  ):
      data_loader = DummyDataLoader([])
      if batch is None or output_dict is None:
          with pytest.raises(ValueError):
              self.postprocessor(batch, output_dict, data_loader)  # type: ignore
          return
  
      expected = json.dumps(
          sanitize(
              {
                  **batch,
                  **(
                      postprocess_func(output_dict)
                      if postprocess_func
                      else output_dict
                  ),
              }
          )
      )
  
      result = self.postprocessor(
          batch, output_dict, data_loader, postprocess_func  # type: ignore
      )
      assert result == expected
  
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 3 for calling the TestSerializer obj's underlying member method code with example usage: obj.test_simple_postprocessor_call(batch, output_dict, postprocess_func) without return types