code: def test_ivf_flat2(self):
      d = self.xq.shape[1] * 8
  
      quantizer = faiss.IndexBinaryFlat(d)
      index = faiss.IndexBinaryIVF(quantizer, d, 8)
      index.cp.min_points_per_centroid = 5  # quiet warning
      index.nprobe = 4
      index.train(self.xt)
      index.add(self.xb)
      Divfflat, _ = index.search(self.xq, 10)
  
      # Some centroids are equidistant from the query points.
      # So the answer will depend on the implementation of the heap.
      self.assertGreater((self.Dref == Divfflat).sum(), 4100)
  
imports: import os
  import numpy
  import unittest
  import faiss
  from common_faiss_tests import compare_binary_result_lists, make_binary_dataset
label_desc: Use image node_id 3 for calling the TestBinaryIVF obj's underlying member method code with example usage: obj.test_ivf_flat2() without return types