old_contents: from bot.action.core.action import Action
  
  
  class FailAction(Action):
      def process(self, event):
          raise NotARealError("simulated error")
  
  
  class NotARealError(Exception):
      pass
  
new_contents: from bot.action.core.action import Action
  
  
  class FailAction(Action):
      def process(self, event):
          if event.command_args == "fatal":
              raise NotARealFatalError("simulated fatal error")
          raise NotARealError("simulated error")
  
  
  class NotARealError(Exception):
      pass
  
  
  class NotARealFatalError(BaseException):
      pass
  
subject: Allow to simulate fatal errors