code: def test_yield_one_epoch_iterates_over_the_data_once(self):
      for test_instances in (self.instances, self.lazy_instances):
          iterator = BasicIterator(batch_size=2)
          batches = list(iterator(test_instances, num_epochs=1))
          # We just want to get the single-token array for the text field in the instance.
          instances = [
              tuple(instance.detach().cpu().numpy())
              for batch in batches
              for instance in batch["text"]["tokens"]
          ]
          assert len(instances) == 5
          self.assert_instances_are_correct(instances)
  
imports: from __future__ import absolute_import
  from collections import Counter
  from allennlp.common import Params
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data import Instance, Token, Vocabulary
  from allennlp.data.dataset_readers.dataset_reader import _LazyInstances
  from allennlp.data.fields import TextField
  from allennlp.data.iterators import BasicIterator
  from allennlp.data.token_indexers import SingleIdTokenIndexer
label_desc: Use image node_id 2 for calling the TestBasicIterator obj's underlying member method code with example usage: obj.test_yield_one_epoch_iterates_over_the_data_once() without return types