code: def active(self, registered_only=True):
          "Returns all active users, e.g. not logged and non-expired session."
          visitors = self.filter(
              expiry_time__gt=timezone.now(),
              end_time=None
          )
          if registered_only:
              visitors = visitors.filter(user__isnull=False)
          return visitorf active(self, registered_only=True):
          "Returns all active users, e.g. not logged and non-expired session."
          visitors = self.filter(
              expiry_time__gt=timezone.now(),
              end_time=None
          )
          if registered_only:
              visitors = visitors.filter(user__isnull=False)
          return visitors
docs: Returns all active users, e.g. not logged and non-expired session.