Why do we need indexPath?

[burakkilic]

Hello;

My code is:

return [collectionView ar_sizeForCellWithIdentifier:@"ItemAllergensCollectionViewCell" indexPath:indexPath fixedWidth:768 configuration:^(__kindof ItemAllergensCollectionViewCell *cell) {
        [cell configureCellWithEntity:self.entity];
    }];

but it crashes because of the indexPath.

 Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM insertObject:atIndex:]: index 2 beyond bounds for empty array'

Why we need indexPath here?

[AugustRush]

This library use indexPath to organized cache(Just two-dimensional array). It's seems indexPath start from 2 rather than 0 here ？