docs: public void update(final Memory mem) {
      if (mem == null) {
        return;
      }
  
      ReservoirLongsSketch rls = ReservoirLongsSketch.heapify(mem);
  
      rls = (rls.getK() <= maxK_ ? rls : rls.downsampledCopy(maxK_));
  
      if (gadget_ == null) {
        createNewGadget(rls, true);
      } else {
        twoWayMergeInternal(rls, true);
      }
    }