code: def _removeBackrefs( senderkey):
      
      try:
          signals = connections[senderkey]
      except KeyError:
          signals = None
      else:
          items = signals.items()
          def allReceivers( ):
              for signal,set in items:
                  for item in set:
                      yield item
          for receiver in allReceivers():
              _killBackref( receiver, senderkey )
docs: Remove all back-references to this senderkey