code: def test_indexed_characters_bow(self):
      s = "Please, take your time"
      inverse_vocab = [
          "P",
          "l",
          "e",
          "a",
          "s",
          ",",
          " ",
          "t",
          "k",
          "y",
          "o",
          "u",
          "r",
          "i",
          "m",
      ]
      positions = [
          [0],
          [1],
          [2, 5, 11, 21],
          [3, 9],
          [4],
          [6],
          [7, 12, 17],
          [8, 18],
          [10],
          [13],
          [14],
          [15],
          [16],
          [19],
          [20],
      ]
      ic = IndexedCharacters(s)
  
      self.assertTrue(np.array_equal(ic.as_np, np.array(list(s))))
      self.assertTrue(
          np.array_equal(ic.string_start, np.arange(len(s)))
      )
      self.assertTrue(ic.inverse_vocab == inverse_vocab)
      self.assertTrue(ic.positions == positions)
  
imports: import re
  import unittest
  import sklearn
  from sklearn.datasets import fetch_20newsgroups
  from sklearn.feature_extraction.text import TfidfVectorizer
  from sklearn.metrics import f1_score
  from sklearn.naive_bayes import MultinomialNB
  from sklearn.pipeline import make_pipeline
  import numpy
  from lime.lime_text import LimeTextExplainer
  from lime.lime_text import IndexedCharacters, IndexedString
label_desc: Use image node_id 4 for calling the TestLimeText obj's underlying member method code with example usage: obj.test_indexed_characters_bow() without return types