1import objc
2
3
4def __len__(self):
5    return self.length()
6
7def __getitem__(self, idx):
8    if isinstance(idx, slice):
9        raise ValueError(idx)
10    return self.indexAtPosition_(idx)
11
12def __add__(self, value):
13    return self.indexPathByAddingIndex_(value)
14
15
16objc.addConvenienceForSelector('length', [
17    ('__len__', __len__),
18])
19objc.addConvenienceForSelector('indexAtPosition:', [
20    ('__getitem__', __getitem__),
21])
22objc.addConvenienceForSelector('indexPathByAddingIndex:', [
23    ('__add__', __add__),
24])
25