code: def test_batch_bow_fallback(self):
      modality = TextModality(
          features=np.asarray([[3, 2, 1], [4, 5, 6]]), ids=["a", "b"]
      )
      modality.build()
      npt.assert_array_equal(
          np.asarray([[3, 2, 1]]), modality.batch_bow(batch_ids=[0])
      )
  
imports: import unittest
  from collections import defaultdict
  import numpy
  import numpy.testing
  from cornac.data import TextModality, ReviewModality
  from cornac.data.text import SPECIAL_TOKENS, DEFAULT_PRE_RULES, BaseTokenizer, Vocabulary, CountVectorizer, TfidfVectorizer
label_desc: Use image node_id 8 for calling the TestTextModality obj's underlying member method code with example usage: obj.test_batch_bow_fallback() without return types