code: def _read(self, file_path):
      for i in range(TOTAL_INSTANCES):
          yield self.text_to_instance(i)
  
imports: from itertools import islice
  from typing import Optional, List, Set
  import pytest
  import torch.distributed
  from allennlp.common import util
  from allennlp.data import Instance
  from allennlp.data.dataset_readers import DatasetReader, WorkerInfo
  from allennlp.data.fields import LabelField
label_desc: Use image node_id 1 for calling the MockDatasetReader obj's underlying member method code with example usage: obj._read(file_path) without return types