code: def test_persistence_ignore(self):
      fname = get_tmpfile("gensim_models_lda_testPersistenceIgnore.tst")
      model = ldamodel.LdaModel(self.corpus, num_topics=2)
      model.save(fname, ignore="id2word")
      model2 = ldamodel.LdaModel.load(fname)
      self.assertTrue(model2.id2word is None)
  
      model.save(fname, ignore=["id2word"])
      model2 = ldamodel.LdaModel.load(fname)
      self.assertTrue(model2.id2word is None)
  
imports: import logging
  import numbers
  import os
  import unittest
  import copy
  import numpy
  from numpy.testing import assert_allclose
  from gensim.corpora import mmcorpus, Dictionary
  from gensim.models import ldamodel, ldamulticore
  from gensim import matutils, utils
  from gensim.test import basetmtests
  from gensim.test.utils import datapath, get_tmpfile, common_texts
label_desc: Use image node_id 15 for calling the TestLdaModel obj's underlying member method code with example usage: obj.test_persistence_ignore() without return types