code: def test_file_backed(self, additional_tokens):
      encoder = text_encoder.ByteTextEncoder(
          additional_tokens=additional_tokens
      )
      with testing.tmp_dir(self.get_temp_dir()) as tmp_dir:
          vocab_fname = os.path.join(tmp_dir, "vocab")
          encoder.save_to_file(vocab_fname)
  
          file_backed_encoder = (
              text_encoder.ByteTextEncoder.load_from_file(vocab_fname)
          )
          self.assertEqual(
              encoder.vocab_size, file_backed_encoder.vocab_size
          )
          self.assertEqual(
              encoder.additional_tokens,
              file_backed_encoder.additional_tokens,
          )
  
imports: from __future__ import unicode_literals
  import os
  from absl.testing import parameterized
  import numpy
  from tensorflow_datasets import testing
  from tensorflow_datasets.core.deprecated.text import text_encoder
label_desc: Use image node_id 3 for calling the ByteTextEncoderTest obj's underlying member method code with example usage: obj.test_file_backed(additional_tokens) without return types