code: def pytest_collection(session):
      # Perform pairwise testing.
      # TODO(kataoka): This is a tentative fix. Discuss its public interface.
      if _pairwise_parameterize == "always":
          pairwise_product_dict = parameterized._pairwise_product_dict
          testing.product_dict = pairwise_product_dict
          parameterized.product_dict = pairwise_product_dict
  
file_path: chainer/tests/conftest.py
imports: import os
  import subprocess
  import sys
  from chainer import testing
  from chainer.testing import parameterized
label_desc: Use image node_id 4 for calling a global function with example usage: pytest_collection(session) without return types