code: def test_compute_tf():
      summarizer = _build_summarizer(EMPTY_STOP_WORDS)
      s0 = Sentence("kicking soccer balls.", Tokenizer("english"))
      s1 = Sentence("eating chicken dumplings.", Tokenizer("english"))
      document = build_document([s0, s1])
      freq = summarizer._compute_tf(document.sentences)
      assert freq["kicking"] == 1 / 6
      assert freq["soccer"] == 1 / 6
      assert freq["balls"] == 1 / 6
      assert freq["eating"] == 1 / 6
      assert freq["chicken"] == 1 / 6
      assert freq["dumplings"] == 1 / 6
  
      document = build_document([s0, s0, s1])
      freq = summarizer._compute_tf(document.sentences)
      assert freq["kicking"] == 2 / 9
      assert freq["soccer"] == 2 / 9
      assert freq["balls"] == 2 / 9
      assert freq["eating"] == 1 / 9
      assert freq["chicken"] == 1 / 9
      assert freq["dumplings"] == 1 / 9
  
file_path: sumy/tests/test_summarizers/test_sum_basic.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import pytest
  from sumy.models.dom._sentence import Sentence
  from sumy.nlp.tokenizers import Tokenizer
  from sumy.summarizers.sum_basic import SumBasicSummarizer
  from sumy.nlp.stemmers import Stemmer
  from ..utils import build_document
label_desc: Use image node_id 10 for calling a global function with example usage: test_compute_tf() without return types