code: static CompactSketch compact(final long[] cache, final boolean empty,
        final short seedHash, final int curCount, final long thetaLong) {
      if ((curCount == 1) && (thetaLong == Long.MAX_VALUE)) {
        return new SingleItemSketch(cache[0], seedHash);
      }
      return new HeapCompactUnorderedSketch(cache, empty, seedHash, curCount, thetaLong);
    }
docs: Constructs this sketch from correct, valid arguments.
  @param cache in compact form
  @param empty The correct <a href="{@docRoot}/resources/dictionary.html#empty">Empty</a>.
  @param seedHash The correct
  <a href="{@docRoot}/resources/dictionary.html#seedHash">Seed Hash</a>.
  @param curCount correct value
  @param thetaLong The correct
  <a href="{@docRoot}/resources/dictionary.html#thetaLong">thetaLong</a>.
  @return a CompactSketch