old_contents: #!/usr/bin/env python3
  import unittest
  
  def main(): # pragma: no cover
      testsuite = unittest.TestLoader().discover('tests/')
      results = unittest.TextTestRunner(verbosity=1).run(testsuite)
      if results.errors or results.failures:
          exit(1)
      else:
          exit(0)
  
  if __name__ == '__main__':
      main()
  
new_contents: #!/usr/bin/env python3
  import os
  import unittest
  
  os.environ['PPP_NLP_CLASSICAL_CONFIG'] = 'example_config.json'
  
  def main(): # pragma: no cover
      testsuite = unittest.TestLoader().discover('tests/')
      results = unittest.TextTestRunner(verbosity=1).run(testsuite)
      if results.errors or results.failures:
          exit(1)
      else:
          exit(0)
  
  if __name__ == '__main__':
      main()
  
subject: Fix tests.