code: def test_factory_5(self):
      index = faiss.index_factory(128, "OPQ16,Flat")
      assert index.sa_code_size() == 128 * 4
      index = faiss.index_factory(128, "OPQ16_64,Flat")
      assert index.sa_code_size() == 64 * 4
      assert index.chain.at(0).d_out == 64
  
imports: import numpy
  import unittest
  import gc
  import faiss
  from faiss.contrib import factory_tools
  from faiss.contrib import datasets
label_desc: Use image node_id 5 for calling the TestFactory obj's underlying member method code with example usage: obj.test_factory_5() without return types