code: def test_default_format(self):
      reader = SequenceTaggingDatasetReader(max_instances=4)
      instances = list(
          reader.read(
              AllenNlpTestCase.FIXTURES_ROOT
              / "data"
              / "sequence_tagging.tsv"
          )
      )
  
      assert len(instances) == 4
      fields = instances[0].fields
      assert [t.text for t in fields["tokens"].tokens] == [
          "cats",
          "are",
          "animals",
          ".",
      ]
      assert fields["tags"].labels == ["N", "V", "N", "N"]
      fields = instances[1].fields
      assert [t.text for t in fields["tokens"].tokens] == [
          "dogs",
          "are",
          "animals",
          ".",
      ]
      assert fields["tags"].labels == ["N", "V", "N", "N"]
      fields = instances[2].fields
      assert [t.text for t in fields["tokens"].tokens] == [
          "snakes",
          "are",
          "animals",
          ".",
      ]
      assert fields["tags"].labels == ["N", "V", "N", "N"]
      fields = instances[3].fields
      assert [t.text for t in fields["tokens"].tokens] == [
          "birds",
          "are",
          "animals",
          ".",
      ]
      assert fields["tags"].labels == ["N", "V", "N", "N"]
  
imports: from allennlp.data.dataset_readers import SequenceTaggingDatasetReader
  from allennlp.common.testing import AllenNlpTestCase
label_desc: Use image node_id 1 for calling the TestSequenceTaggingDatasetReader obj's underlying member method code with example usage: obj.test_default_format() without return types