Traceback (most recent call last):
  File "main.py", line 399, in <module>
    _, res1 = functions[part](files)
  File "./pipeline_utils.py", line 66, in wrapper
    return callable_(*args, **kwargs)
  File "./libs/joblib/memory.py", line 568, in __call__
    return self._cached_call(args, kwargs)[0]
  File "./libs/joblib/memory.py", line 534, in _cached_call
    out, metadata = self.call(*args, **kwargs)
  File "./libs/joblib/memory.py", line 734, in call
    output = self.func(*args, **kwargs)
  File "main.py", line 352, in get_top_news
    topics_cat_full, topics_cat_short = find_topics(articles)
  File "./pipeline_utils.py", line 66, in wrapper
    return callable_(*args, **kwargs)
  File "./libs/joblib/memory.py", line 568, in __call__
    return self._cached_call(args, kwargs)[0]
  File "./libs/joblib/memory.py", line 534, in _cached_call
    out, metadata = self.call(*args, **kwargs)
  File "./libs/joblib/memory.py", line 734, in call
    output = self.func(*args, **kwargs)
  File "main.py", line 306, in find_topics
    res.extend(filter_and_rank_language(rus, ru_topics, 'ru'))
  File "main.py", line 99, in filter_and_rank_language
    data = vectorizer.fit_transform(topics_unique)
  File "./libs/sklearn/feature_extraction/text.py", line 1058, in fit_transform
    self.fixed_vocabulary_)
  File "./libs/sklearn/feature_extraction/text.py", line 989, in _count_vocab
    raise ValueError("empty vocabulary; perhaps the documents only"
ValueError: empty vocabulary; perhaps the documents only contain stop words