code: def test_PQ(self):
      self.do_test("IVF64,PQ4np")
  
imports: import unittest
  import faiss
  import numpy
  from common_faiss_tests import get_dataset_2
  from faiss.contrib import datasets, evaluation, big_batch_search
  from faiss.contrib.exhaustive_search import knn_ground_truth, range_ground_truth, range_search_gpu, range_search_max_results, exponential_query_iterator
label_desc: Use image node_id 3 for calling the TestBigBatchSearch obj's underlying member method code with example usage: obj.test_PQ() without return types