Get the NSIndexPaths for visible rows on a UICollectionView, sorted by row. For some reason [collectionView indexPathsForVisibleItems] returns unsorted items

sortedVisibleIndexPaths.m

// Get visible rows and sort them by row
- (NSArray *)sortedVisibleIndexPaths {
    NSArray *visibleItems = [self.collectionView indexPathsForVisibleItems];
    // visible items is NOT SORTED! lol
    NSSortDescriptor *rowDescriptor = [[NSSortDescriptor alloc] initWithKey:@"row" ascending:YES];
    NSMutableArray *sortedRows = [[visibleItems sortedArrayUsingDescriptors:@[rowDescriptor]] mutableCopy];
    return sortedRows;
}