code: @Benchmark
    public int unionAndIter(BitmapsForUnion state)
    {
      ImmutableBitmap intersection = factory.union(Arrays.asList(state.bitmaps));
      return iter(intersection);
    }
docs: Benchmark of cumulative cost of bitmap union with subsequent iteration over the result. This is a pattern from
  query processing on historical nodes, when filters like {@link org.apache.druid.segment.filter.DimensionPredicateFilter},
  {@link org.apache.druid.query.filter.RegexDimFilter}, {@link org.apache.druid.query.filter.SearchQueryDimFilter} and similar are
  used.