code: def test_bad_bytes(self):
      valid_unicode = "你"
      bad_bytes = [220 + len(self.vocab_list) + 1]
      bad_ids = self.encoder.encode("你") + bad_bytes
      text = self.encoder.decode(bad_ids)
      # Valid unicode character preserved
      self.assertEqual(valid_unicode, text[0])
      # Invalid byte converted to unknown character
      self.assertEqual("\uFFFD", text[1])
  
imports: from __future__ import unicode_literals
  import os
  from absl.testing import parameterized
  import tensorflow
  from tensorflow_datasets import testing
  from tensorflow_datasets.core import utils
  from tensorflow_datasets.core.deprecated.text import subword_text_encoder
  from tensorflow_datasets.core.deprecated.text import text_encoder
label_desc: Use image node_id 4 for calling the SubwordTextEncoderTest obj's underlying member method code with example usage: obj.test_bad_bytes() without return types