code: static ReservoirLongsSketch getInstance(final long[] data, final long itemsSeen,
                                            final ResizeFactor rf, final int k) {
      return new ReservoirLongsSketch(data, itemsSeen, rf, k);
    }
docs: Thin wrapper around private constructor
  
  @param data Reservoir items as long[]
  @param itemsSeen Number of items presented to the sketch so far
  @param rf <a href="{@docRoot}/resources/dictionary.html#resizeFactor">See Resize Factor</a>
  @param k Maximum reservoir size
  @return New sketch built with the provided inputs