old_contents: class TestException(Exception):
      pass
  
  class TestStatusFailed(TestException):
      pass
  
  class TestExpectFailed(TestException):
      pass
  
new_contents: class TestException(Exception):
      pass
  
  class TestCheckFailed(TestException):
      pass
  
  class TestStatusFailed(TestException):
      pass
  
  class TestExpectFailed(TestException):
      pass
  
subject: Add exception