old_contents: import sys
  
  if sys.version_info[0] > 2:
      import unittest
  else:
      import unittest2 as unittest
  
  if __name__ == '__main__':
      unittest.main()
  
new_contents: import sys
  
  if sys.version_info < (2, 7):
      import unittest2 as unittest
  else:
      import unittest
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Fix unittest2 import check