code: def _check_build(self):
      self._check_model()
      if self.topic_dict is None:
          raise Exception("Must call build() method.")
  
imports: import time
  from ..None import utils
  from ..imports import *
  from .None import preprocessor
  from .None import textutils
label_desc: Use image node_id 23 for calling the TopicModel obj's underlying member method code with example usage: obj._check_build() without return types