code: def test_save_model(self):
      self.save_model(
          VowpalWabbitContextualBandit()
          .setPassThroughArgs("--cb_explore_adf --epsilon 0.2 --quiet")
          .setUseBarrierExecutionMode(False),
      )
  
imports: import os
  import unittest
  import tempfile
  import pyspark
  from synapsemltest.spark import *
  from synapse.ml.vw import VowpalWabbitContextualBandit
  from synapse.ml.vw import VowpalWabbitFeaturizer
  from synapse.ml.vw import VectorZipper
  from pyspark.ml.tuning import ParamGridBuilder
  from pyspark.sql.types import *
  from pyspark.ml import Pipeline
  from pyspark.ml.wrapper import *
  from pyspark.ml.common import inherit_doc, _java2py, _py2java
  from pyspark.sql.utils import AnalysisException
label_desc: Use image node_id 4 for calling the VowpalWabbitSpec obj's underlying member method code with example usage: obj.test_save_model() without return types