code: def test_alpha_auto(self):
      self.assertRaises(RuntimeError, self.class_, alpha="auto")
  
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 2 for calling the TestLdaMulticore obj's underlying member method code with example usage: obj.test_alpha_auto() without return types