class CommentOptions(dbsettings.Group):
    comment_limit = dbsettings.IntegerValue('Maximum number of comments a blog can receive')

class BlogEntry(models.Model):
    title = models.CharField(maxlength=255)
    body = models.TextField()
        
    options = CommentOptions()
        
    def can_receive_comments(self):
        return self.comments.count() < BlogEntry.options.comment_limit

class ThreadOptions(dbsettings.Group):
    popularity_threshold = dbsettings.PositiveIntegerValue()

class Thread(models.Model):
    title = models.CharField(maxlength=255)

    options = ThreadOptions()

    def is_popular(self):
        return self.posts.count() > Topic.options.popularity_threshold

class Post(models.Model):
    thread = models.ForeignKey(Thread, related_name='posts')
    author = models.ForeignKey(User)
    body = models.TextField()