code: def test_stopword_modification(
      self, sentence_attacked_text, entailment_attacked_text
  ):
      constraint = (
          textattack.constraints.pre_transformation.StopwordModification()
      )
      assert constraint._get_modifiable_indices(
          sentence_attacked_text
      ) == (
          set(range(len(sentence_attacked_text.words)))
          - {6, 8, 10, 15, 17}
      )
      assert constraint._get_modifiable_indices(
          entailment_attacked_text
      ) == (
          set(range(len(entailment_attacked_text.words)))
          - {
              1,
              2,
              3,
              8,
              9,
              11,
              16,
              17,
              20,
              22,
              25,
              31,
              34,
              39,
              40,
              41,
              43,
              44,
          }
      )
  
file_path: TextAttack/tests/test_constraints/test_pretransformation_constraints.py
imports: import collections
  import pytest
  import textattack
label_desc: Use image node_id 6 for calling the TestPretransformationConstraints obj's underlying member method code with example usage: obj.test_stopword_modification(sentence_attacked_text, entailment_attacked_text) without return types