code: def test_article_example():
      """Source: http://www.prevko.cz/dite/skutecne-pribehy-deti"""
      parser = PlaintextParser.from_string(
          load_resource("articles/prevko_cz_1.txt"), Tokenizer("czech")
      )
      summarizer = LexRankSummarizer(stem_word)
      summarizer.stop_words = get_stop_words("czech")
  
      sentences = summarizer(parser.document, 20)
      assert len(sentences) == 20
  
imports: from __future__ import absolute_import
  from __future__ import division, print_function, unicode_literals
  import math
  import numpy
  import pytest
  import sumy.summarizers.lex_rank
  from sumy.nlp.stemmers.czech import stem_word
  from sumy.nlp.tokenizers import Tokenizer
  from sumy.parsers.plaintext import PlaintextParser
  from sumy.summarizers.lex_rank import LexRankSummarizer
  from sumy.utils import get_stop_words
  from ..utils import build_document, load_resource
label_desc: Use image node_id 6 for calling a global function with example usage: test_article_example() without return types