code: def test_keras_tokenizer(self):
      tokenizer = KerasTokenizer(
          filters="", lower=False, oov_token="<unk>"
      )
      tokenizer.fit(["a b c d"])
      encoded = tokenizer.encode("a b e")
      self.assertEqual([2, 3, 1], encoded)
      decoded = tokenizer.decode(encoded)
      self.assertEqual("a b <unk>", decoded)
      self.assertEqual(5, tokenizer.vocab_size)
      self.assertEqual(
          {"a", "b", "c", "d", "<unk>"}, tokenizer.token_index.keys()
      )
      self.assertEqual(
          {1, 2, 3, 4, 5}, set(tokenizer.token_index.values())
      )
  
imports: import unittest
  from headliner.preprocessing.keras_tokenizer import KerasTokenizer
label_desc: Use image node_id 1 for calling the TestKerasTokenizer obj's underlying member method code with example usage: obj.test_keras_tokenizer() without return types