old_contents: #!/usr/bin/env python
  # -*- coding: UTF-8 -*-
  # vim: fileencoding=utf-8 autoindent tabstop=4 shiftwidth=4 expandtab softtabstop=4 filetype=python
  
  import unittest
  from tests.test_transition import TestTransition
  
  def main():
      discover = unittest.defaultTestLoader.discover('./tests', pattern='test*.py')
      runner=unittest.TextTestRunner(verbosity=2)
      runner.run(discover)
  
  if __name__ == '__main__':
      main()
  
  
  
new_contents: #!/usr/bin/env python
  # -*- coding: UTF-8 -*-
  # vim: fileencoding=utf-8 autoindent tabstop=4 shiftwidth=4 expandtab softtabstop=4 filetype=python
  
  import unittest
  
  def main():
      discover = unittest.defaultTestLoader.discover('./tests', pattern='test*.py')
      runner=unittest.TextTestRunner(verbosity=2)
      runner.run(discover)
  
  if __name__ == '__main__':
      main()
  
  
  
subject: delete useless import