def getPosts(self, how_many = None):
        """Return the latest 'how_many' posts, in reverse database order.

        XXX Really, it should be based on modtime.  Which is broken.
        """
        if how_many is None or how_many > self.next_id:
            how_many = self.next_id
        return (self.getOne(id-1-self.next_id) for id in range(how_many))
dataset/ETHPy150Open twisted/nevow/examples/blogengine/axiomstore.py/Blog.getPosts/swapped operands of `-`