def METHOD_NAME(self, points, value):
    last_wall = None
    for wall in points:
        if last_wall is None:
            last_wall = tuple(self.transform(wall).astype(np.int32))
            continue
        this_wall = tuple(self.transform(wall).astype(np.int32))
        cv2.line(self.grid, this_wall, last_wall, value, 1)
        last_wall = this_wall