def delete(self, using=None):
        """ Deletes the post instance. """
        if self.is_alone:
            # The default way of operating is to trigger the deletion of the associated topic
            # only if the considered post is the only post embedded in the topic
            self.topic.delete()
        else:
            super(AbstractPost, self).delete(using)
            self.topic.update_trackers()
Deletes the post instance.