old_contents: import glob
  import os
  import sys
  import unittest
  
  
  test_root = os.path.dirname(os.path.abspath(__file__))
  test_files = glob.glob(os.path.join(test_root, 'test_*.py'))
  
  os.chdir(test_root)
  sys.path.insert(0, os.path.dirname(test_root))
  sys.path.insert(0, test_root)
  test_names = [os.path.basename(name)[:-3] for name in test_files]
  
  suite = unittest.defaultTestLoader.loadTestsFromNames(test_names)
  unittest.TextTestRunner().run(suite)
  
new_contents: import glob
  import os
  import sys
  import unittest
  
  
  test_root = os.path.dirname(os.path.abspath(__file__))
  test_files = glob.glob(os.path.join(test_root, 'test_*.py'))
  
  os.chdir(test_root)
  sys.path.insert(0, os.path.dirname(test_root))
  sys.path.insert(0, test_root)
  test_names = [os.path.basename(name)[:-3] for name in test_files]
  
  if __name__ == '__main__':
      suite = unittest.defaultTestLoader.loadTestsFromNames(test_names)
      ret = unittest.TextTestRunner().run(suite)
      retcode = 0
      if ret.failures or ret.errors:
          retcode = 1
      sys.exit(retcode)
  
subject: return exec status code