code: def test_unescape_token(self):
      unescaped = text_encoder._unescape_token(
          "\\70;oo\\33; \\66;ar.\\10;under\\uscore back\\\\slash_"
      )
  
      self.assertEqual("Foo! Bar.\nunder_score back\\slash", unescaped)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import collections
  import io
  import os
  import random
  import shutil
  import string
  import mock
  import six
  from six.moves import range
  from tensor2tensor.data_generators import text_encoder
  import tensorflow.compat.v1
label_desc: Use image node_id 2 for calling the EscapeUnescapeTokenTest obj's underlying member method code with example usage: obj.test_unescape_token() without return types