code: def test_unit(cov_report="term"):
      """Run all unit tests. Returns exit code."""
      orig_dir = os.getcwd()
      os.chdir(ROOT_DIR)
      try:
          _clear_imageio()
          _enable_faulthandler()
          return pytest.main(
              [
                  "-v",
                  "--cov",
                  "imageio",
                  "--cov-config",
                  ".coveragerc",
                  "--cov-report",
                  cov_report,
                  "tests",
              ]
          )
      finally:
          os.chdir(orig_dir)
          import imageio
  
          print("Tests were performed on", str(imageio))
  
imports: import os
  import sys
  import pytest
label_desc: Use image node_id 1 for calling a global function with example usage: test_unit(cov_report) and returns: pytest