code: def test_nprobe_3(self):
      index = faiss.index_factory(32, "IVF32,SQ8,RFlat")
      ps = faiss.ParameterSpace()
      ps.set_index_parameter(index, "nprobe", 5)
      index2 = faiss.downcast_index(index.base_index)
      self.assertEqual(index2.nprobe, 5)
  
file_path: faiss/tests/test_autotune.py
imports: import unittest
  import faiss
label_desc: Use image node_id 3 for calling the TestParameterSpace obj's underlying member method code with example usage: obj.test_nprobe_3() without return types