code: def test_8bit_direct(self):
      for d in 13, 16, 24:
          for metric_type in (
              faiss.METRIC_L2,
              faiss.METRIC_INNER_PRODUCT,
          ):
              self.subtest_8bit_direct(metric_type, d)
  
imports: from __future__ import absolute_import, division, print_function
  import unittest
  import faiss
  import numpy
  from common_faiss_tests import Randu10k, get_dataset_2, Randu10kUnbalanced
label_desc: Use image node_id 2 for calling the TestSQByte obj's underlying member method code with example usage: obj.test_8bit_direct() without return types