code: def test_idfs_from_dictionary(self):
      model = OkapiBM25Model(
          dictionary=self.dictionary,
          k1=self.k1,
          b=self.b,
          epsilon=self.epsilon,
      )
  
      actual_dog_idf = model.idfs[self.dictionary.token2id["dog"]]
      actual_cat_idf = model.idfs[self.dictionary.token2id["cat"]]
      actual_mouse_idf = model.idfs[self.dictionary.token2id["mouse"]]
      actual_lion_idf = model.idfs[self.dictionary.token2id["lion"]]
  
      self.assertAlmostEqual(self.expected_dog_idf, actual_dog_idf)
      self.assertAlmostEqual(self.expected_cat_idf, actual_cat_idf)
      self.assertAlmostEqual(self.expected_mouse_idf, actual_mouse_idf)
      self.assertAlmostEqual(self.expected_lion_idf, actual_lion_idf)
  
imports: from collections import defaultdict
  import math
  import unittest
  from gensim.models.bm25model import BM25ABC
  from gensim.models import OkapiBM25Model, LuceneBM25Model, AtireBM25Model
  from gensim.corpora import Dictionary
label_desc: Use image node_id 3 for calling the OkapiBM25ModelTest obj's underlying member method code with example usage: obj.test_idfs_from_dictionary() without return types