code: def __init__(self):
      super().__init__()
      self._token_indexers = {"tokens": SingleIdTokenIndexer()}
      self._tokenizer = SpacyTokenizer()
  
imports: from typing import Iterable
  import pytest
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data.dataset_readers import DatasetReader, InterleavingDatasetReader
  from allennlp.data.data_loaders import MultiProcessDataLoader
  from allennlp.data.fields import TextField
  from allennlp.data.instance import Instance
  from allennlp.data.token_indexers import SingleIdTokenIndexer
  from allennlp.data.tokenizers import SpacyTokenizer
  from allennlp.data.vocabulary import Vocabulary
label_desc: Use image node_id 1 to create a new PlainTextReader object from inherited base classes: DatasetReader with example: obj = PlainTextReader()