docstr: Test if CoherenceModel works with document without tokens
docstr_tok: ["Test","if","CoherenceModel","works","with","document","without","tokens"]
code: def testEmptyList(self):
      """Test if CoherenceModel works with document without tokens"""
      texts = self.texts + [[]]
      cm = CoherenceModel(
          model=self.ldamodel, texts=texts, coherence="c_v", processes=1
      )
      cm.get_coherence()
  
imports: import logging
  import unittest
  import multiprocessing
  from functools import partial
  import numpy
  from gensim.matutils import argsort
  from gensim.models.coherencemodel import CoherenceModel, BOOLEAN_DOCUMENT_BASED
  from gensim.models.ldamodel import LdaModel
  from gensim.test.utils import get_tmpfile, common_texts, common_dictionary, common_corpus
label_desc: Use image node_id 25 for calling the TestCoherenceModel obj's underlying member method code with example usage: obj.testEmptyList() without return types