docs: def getFactory(self):
          """
          Return a server factory which creates AMP protocol instances.
          """
          factory = ServerFactory()
          def protocol():
              proto = CredReceiver()
              proto.portal = Portal(
                  self.loginSystem,
                  [self.loginSystem,
                   OneTimePadChecker(self._oneTimePads)])
              return proto
          factory.protocol = protocol
          return factory