code: def test_reserved_token_chars_not_in_alphabet(self):
      corpus = "dog"
      token_counts = collections.Counter(corpus.split(" "))
      encoder1 = text_encoder.SubwordTextEncoder.build_to_target_size(
          100, token_counts, 2, 100
      )
      filename = os.path.join(self.test_temp_dir, "out.voc")
      encoder1.store_to_file(filename)
      encoder2 = text_encoder.SubwordTextEncoder(filename=filename)
  
      self.assertEqual(encoder1._alphabet, encoder2._alphabet)
  
      for t in text_encoder.RESERVED_TOKENS:
          for c in t:
              # Verify that encoders can encode all reserved token chars.
              encoder1.encode(c)
              encoder2.encode(c)
  
imports: import collections
  import io
  import os
  import random
  import shutil
  import string
  import mock
  from six.moves import range
  import tensorflow.compat.v1
  from trax.data import text_encoder
label_desc: Use image node_id 10 for calling the SubwordTextEncoderTest obj's underlying member method code with example usage: obj.test_reserved_token_chars_not_in_alphabet() without return types