code: def test_parenthesis_refine_2(self):
      # Refine applies on the whole index including pre-transforms
      index = faiss.index_factory(
          50, "PCA32,IVF32,Flat,Refine(PQ25x12)"
      )
      rf = faiss.downcast_index(index.refine_index)
      self.assertEqual(rf.pq.M, 25)
  
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 13 for calling the TestFactory obj's underlying member method code with example usage: obj.test_parenthesis_refine_2() without return types