code: def _get_signal_event(self, s):
          '''
          Get the event for a signal.
  
          Checks if the signal has been enabled and raises a
          ``ValueError`` if not.
          '''
          try:
              return self._signal_events[int(s)]
          except KeyError:
              raise ValueError('Signal {} has not been enabled'.format(s)f _get_signal_event(self, s):
          '''
          Get the event for a signal.
  
          Checks if the signal has been enabled and raises a
          ``ValueError`` if not.
          '''
          try:
              return self._signal_events[int(s)]
          except KeyError:
              raise ValueError('Signal {} has not been enabled'.format(s))
docs: Get the event for a signal.
  
          Checks if the signal has been enabled and raises a
          ``ValueError`` if not.