code: def test_textrank_summary():
      assert len(DOC_1.generate_textrank_summary(ratio=0.5)) == 2
  
imports: import re
  from unittest import mock
  import pytest
  import spacy
  import numpy
  from fakeredis import FakeRedis
  from textpipe.doc import Doc, TextpipeMissingModelException, RedisIDFWeightingMismatchException
  from textpipe.wrappers import RedisKeyedVectors
label_desc: Use image node_id 15 for calling a global function with example usage: test_textrank_summary() without return types