docs: def register(self, model_or_iterable, moderation_class):
          """
          Register a model or a list of models for comment moderation,
          using a particular moderation class.
  
          Raise ``AlreadyModerated`` if any of the models are already
          registered.
  
          """
          if isinstance(model_or_iterable, ModelBase):
              model_or_iterable = [model_or_iterable]
          for model in model_or_iterable:
              if model in self._registry:
                  raise AlreadyModerated(
                      "The model '%s' is already being moderated" % model._meta.verbose_name
                  )
              self._registry[model] = moderation_class(model)