class_docstr: Storage Structure of Topic model, including vocabulary and word topic count.
      
code: def num_topics(self):
      return self.__num_topics
  
imports: import os
  from collections import OrderedDict
  import numpy
  from tqdm import tqdm
  from paddlehub.common.logger import logger
  from lda_news.vocab import Vocab, WordCount
label_desc: Use image node_id 8 for calling the TopicModel obj's underlying member method code with example usage: obj.num_topics() and returns: self