code: def pytest_configure(config):
      # config is initialized here rather than in pytest.ini so that `pytest
      # --pyargs matplotlib` (which would not find pytest.ini) works.  The only
      # entries in pytest.ini set minversion (which is checked earlier),
      # testpaths/python_files, as they are required to properly find the tests
      for key, value in [
          ("markers", "flaky: (Provided by pytest-rerunfailures.)"),
          ("markers", "timeout: (Provided by pytest-timeout.)"),
          (
              "markers",
              "backend: Set alternate Matplotlib backend temporarily.",
          ),
          (
              "markers",
              "baseline_images: Compare output against references.",
          ),
          ("markers", "pytz: Tests that require pytz to be installed."),
          ("filterwarnings", "error"),
          (
              "filterwarnings",
              "ignore:.*The py23 module has been deprecated:DeprecationWarning",
          ),
          (
              "filterwarnings",
              r"ignore:DynamicImporter.find_spec\(\) not found; "
              r"falling back to find_module\(\):ImportWarning",
          ),
      ]:
          config.addinivalue_line(key, value)
  
      matplotlib.use("agg", force=True)
      matplotlib._called_from_pytest = True
      matplotlib._init_tests()
  
file_path: matplotlib/lib/matplotlib/testing/conftest.py
imports: import pytest
  import sys
  import matplotlib
  from matplotlib import _api
label_desc: Use image node_id 1 for calling a global function with example usage: pytest_configure(config) without return types