5 def __init__(self, cover):
12 def build(self, w, h):
13 raise NotImplementedError()
15 def apply(self, img, x, y, w=None, h=None):
16 my_img = self.build(w, h)
17 if my_img is not None:
20 (round(x), round(y - self.margin_top)),
21 my_img if self.transparency else None