- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSIndexPath *indexPathCopy = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section];
    NSString *sizeString = self.heightCache[indexPathCopy];
    if (sizeString) {
        CGSize size = CGSizeFromString(sizeString);
        NSLog(@"estimatedHeightForRowAtIndexPath %f row %ld",size.height, (long)indexPath.row);
        return size.height;
    }

    return UITableViewAutomaticDimension;
}

- (void)tableView:(UITableView *)tableView didEndDisplayingCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    NSIndexPath *indexPathCopy = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section];
    self.heightCache[indexPathCopy] = NSStringFromCGSize(cell.frame.size);
}