class_docstr: Tests XLNet utils.
      
code: def test_load_pretrained_model_AND_transform_xlnet_to_texar_config(
      self,
  ):
      pretrained_model_dir = PretrainedXLNetMixin.download_checkpoint(
          pretrained_model_name="xlnet-base-cased"
      )
  
      info = list(os.walk(pretrained_model_dir))
      _, _, files = info[0]
      self.assertIn("spiece.model", files)
      self.assertIn("xlnet_model.ckpt.meta", files)
      self.assertIn("xlnet_model.ckpt.data-00000-of-00001", files)
      self.assertIn("xlnet_model.ckpt.index", files)
      self.assertIn("xlnet_config.json", files)
  
      model_config = PretrainedXLNetMixin._transform_config(
          pretrained_model_name="xlnet-base-cased",
          cache_dir=pretrained_model_dir,
      )
  
      expected_config = {
          "head_dim": 64,
          "ffn_inner_dim": 3072,
          "hidden_dim": 768,
          "activation": "gelu",
          "num_heads": 12,
          "num_layers": 12,
          "vocab_size": 32000,
          "untie_r": True,
      }
  
      self.assertDictEqual(model_config, expected_config)
  
imports: import os
  import tensorflow
  from texar.tf.modules.pretrained.xlnet import *
  from texar.tf.utils.test import pretrained_test
label_desc: Use image node_id 1 for calling the XLNetUtilsTest obj's underlying member method code with example usage: obj.test_load_pretrained_model_AND_transform_xlnet_to_texar_config() without return types