docs: def _run(self):
          """Run the worker function with some custom exception handling."""
          try:
              # Run the worker
              self.worker()
          except SystemExit as ex:
              # sys.exit() was called
              if isinstance(ex.code, int):
                  if ex.code is not None and ex.code != 0:
                      # A custom exit code was specified
                      self._shutdown(
                          'Exiting with non-zero exit code {exitcode}'.format(
                              exitcode=ex.code),
                          ex.code)
              else:
                  # A message was passed to sys.exit()
                  self._shutdown(
                      'Exiting with message: {msg}'.format(msg=ex.code), 1)
          except Exception as ex:
              if self.detach:
                  self._shutdown('Dying due to unhandled {cls}: {msg}'.format(
                      cls=ex.__class__.__name__, msg=str(ex)), 127)
              else:
                  # We're not detached so just raise the exception
                  raise
  
          self._shutdown('Shutting down normally')