code: def test_initial_model(self):
      featurized_data = self.get_data()
      estimator1 = (
          VowpalWabbitContextualBandit()
          .setPassThroughArgs("--cb_explore_adf --epsilon 0.2 --quiet")
          .setUseBarrierExecutionMode(False)
      )
  
      model1 = estimator1.fit(featurized_data)
  
      estimator2 = (
          VowpalWabbitContextualBandit()
          .setPassThroughArgs("--cb_explore_adf --epsilon 0.2 --quiet")
          .setUseBarrierExecutionMode(False)
      )
      estimator2.setInitialModel(model1.getNativeModel())
  
      estimator2.fit(featurized_data)
  
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 5 for calling the VowpalWabbitSpec obj's underlying member method code with example usage: obj.test_initial_model() without return types