old_contents: import sys
  import unittest
  
  loader = unittest.TestLoader()
  start_dir = '.'
  SUITE = loader.discover(start_dir, pattern='*_test.py')
  
  runner = unittest.TextTestRunner()
  
  ret = not runner.run(SUITE).wasSuccessful()
  sys.exit(ret)
  
new_contents: import sys
  import unittest
  
  LOADER = unittest.TestLoader()
  SUITE = LOADER.discover(start_dir=".", pattern='*_test.py')
  RUNNER = unittest.TextTestRunner()
  sys.exit(not RUNNER.run(SUITE).wasSuccessful())
  
subject: fix some minor quality issues