code: public CompactSketch intersect(final Sketch a, final Sketch b) {
      return intersect(a, b, true, null);
    }
docs: Perform intersect set operation on the two given sketch arguments and return the result as an
  ordered CompactSketch on the heap.
  @param a The first sketch argument
  @param b The second sketch argument
  @return an ordered CompactSketch on the heap