code: def do_exit(self, arg_list: List[str]) -> bool:
          
          # If an argument was provided
          if arg_list:
              try:
                  self.exit_code = int(arg_list[0])
              except ValueError:
                  self.perror("{} isn't a valid integer exit code".format(arg_list[0]))
                  self.exit_code = -1
  
          self._should_quit = True
          return self._STOP_AND_EXIT
docs: Exit the application with an optional exit code.
  
  Usage:  exit [exit_code]
      Where:
          * exit_code - integer exit code to return to the shell