code: def test_length_score(self):
      score = sub._score(sample1, fields=["hypothesis", "premise"])
      self.assertEqual(score, 0)
  
imports: import unittest
  from textflint.generation.subpopulation.UT import PhraseSubPopulation
  from textflint.input.component.sample import NLISample
label_desc: Use image node_id 1 for calling the TestPhraseSubPopulation obj's underlying member method code with example usage: obj.test_length_score() without return types