code: def test_parenthesis(self):
      index = faiss.index_factory(50, "IVF32(PQ25),Flat")
      quantizer = faiss.downcast_index(index.quantizer)
      self.assertEqual(quantizer.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 10 for calling the TestFactory obj's underlying member method code with example usage: obj.test_parenthesis() without return types