text: import os
  
  import pytest
  from transformers import AutoModelForQuestionAnswering, AutoTokenizer
  from transformers_interpret import QuestionAnsweringExplainer
  from transformers_interpret.errors import (
      AttributionTypeNotSupportedError,
      InputIdsNotCalculatedError,
  )
  
  DISTILBERT_QA_MODEL = AutoModelForQuestionAnswering.from_pretrained(
      "mrm8488/bert-tiny-5-finetuned-squadv2"
  )
  DISTILBERT_QA_TOKENIZER = AutoTokenizer.from_pretrained(
      "mrm8488/bert-tiny-5-finetuned-squadv2"
  )
  
  
  def test_question_answering_explainer_init_distilbert():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      assert qa_explainer.attribution_type == "lig"
      assert qa_explainer.attributions is None
      assert qa_explainer.position == 0
  
  
  def test_question_answering_explainer_init_attribution_type_error():
      with pytest.raises(AttributionTypeNotSupportedError):
          QuestionAnsweringExplainer(
              DISTILBERT_QA_MODEL,
              DISTILBERT_QA_TOKENIZER,
              attribution_type="UNSUPPORTED",
          )
  
  
  def test_question_answering_encode():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
  
      _input = "this is a sample of text to be encoded"
      tokens = qa_explainer.encode(_input)
      assert isinstance(tokens, list)
      assert tokens[0] != qa_explainer.cls_token_id
      assert tokens[-1] != qa_explainer.sep_token_id
      assert len(tokens) >= len(_input.split(" "))
  
  
  def test_question_answering_decode():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is bob"
      input_ids, _, _ = qa_explainer._make_input_reference_pair(
          explainer_question, explainer_text
      )
      decoded = qa_explainer.decode(input_ids)
      assert decoded[0] == qa_explainer.tokenizer.cls_token
      assert decoded[-1] == qa_explainer.tokenizer.sep_token
      assert (
          " ".join(decoded[1:-1])
          == explainer_question.lower() + " [SEP] " + explainer_text.lower()
      )
  
  
  def test_question_answering_word_attributions():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is bob"
      word_attributions = qa_explainer(explainer_question, explainer_text)
      assert isinstance(word_attributions, dict)
      assert "start" in word_attributions.keys()
      assert "end" in word_attributions.keys()
      assert len(word_attributions["start"]) == len(word_attributions["end"])
  
  
  def test_question_answering_word_attributions_input_ids_not_calculated():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
  
      with pytest.raises(ValueError):
          qa_explainer.word_attributions
  
  
  def test_question_answering_start_pos():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text)
      start_pos = qa_explainer.start_pos
      assert start_pos == 10
  
  
  def test_question_answering_end_pos():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text)
      end_pos = qa_explainer.end_pos
      assert end_pos == 10
  
  
  def test_question_answering_start_pos_input_ids_not_calculated():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      with pytest.raises(InputIdsNotCalculatedError):
          qa_explainer.start_pos
  
  
  def test_question_answering_end_pos_input_ids_not_calculated():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      with pytest.raises(InputIdsNotCalculatedError):
          qa_explainer.end_pos
  
  
  def test_question_answering_predicted_answer():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text)
      predicted_answer = qa_explainer.predicted_answer
      assert predicted_answer == "bob"
  
  
  def test_question_answering_predicted_answer_input_ids_not_calculated():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      with pytest.raises(InputIdsNotCalculatedError):
          qa_explainer.predicted_answer
  
  
  def test_question_answering_visualize():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text)
      qa_explainer.visualize()
  
  
  def test_question_answering_visualize_save():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text)
  
      html_filename = "./test/qa_test.html"
      qa_explainer.visualize(html_filename)
      assert os.path.exists(html_filename)
      os.remove(html_filename)
  
  
  def test_question_answering_visualize_save_append_html_file_ending():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text)
  
      html_filename = "./test/qa_test"
      qa_explainer.visualize(html_filename)
      assert os.path.exists(html_filename + ".html")
      os.remove(html_filename + ".html")
  
  
  def xtest_question_answering_custom_steps():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text, n_steps=1)
  
  
  def xtest_question_answering_custom_internal_batch_size():
      qa_explainer = QuestionAnsweringExplainer(
          DISTILBERT_QA_MODEL, DISTILBERT_QA_TOKENIZER
      )
      explainer_question = "what is his name ?"
      explainer_text = "his name is Bob"
      qa_explainer(explainer_question, explainer_text, internal_batch_size=1)
  