code: def test_errors(self):
      # Ensure that trying to retrieve a key not in JSON data errors
      self.write_test_ppid_dataset(data_format="json")
  
      question_field = data.Field(sequential=True)
      label_field = data.Field(sequential=False)
      fields = {
          "qeustion1": ("q1", question_field),
          "question2": ("q2", question_field),
          "label": ("label", label_field),
      }
  
      with self.assertRaises(ValueError):
          data.TabularDataset(
              path=self.test_ppid_dataset_path,
              format="json",
              fields=fields,
          )
  
file_path: decanlp/text/test/data/test_dataset.py
imports: from __future__ import unicode_literals
  import torchtext.data
  from ..common.torchtext_test_case import TorchtextTestCase
label_desc: Use image node_id 3 for calling the TestDataset obj's underlying member method code with example usage: obj.test_errors() without return types