Don't require the `--structure` argument.
{
        if (params.num_buckets_cutoff)
        {
            for (auto & elem : table)
            {
                Histogram & histogram = elem.getMapped();
                if (histogram.buckets.size() < params.num_buckets_cutoff)
                {
                    histogram.buckets.clear();
                    histogram.total = 0;
                }
            }
        }