code: static final void hipAndKxQIncrementalUpdate(final AbstractHllArray host, final int oldValue,
        final int newValue) {
      assert newValue > oldValue;
      final int configK = 1 << host.getLgConfigK();
      //update hipAccum BEFORE updating kxq0 and kxq1
      double kxq0 = host.getKxQ0();
      double kxq1 = host.getKxQ1();
      host.addToHipAccum(configK / (kxq0 + kxq1));
      //update kxq0 and kxq1; subtract first, then add.
      if (oldValue < 32) { host.putKxQ0(kxq0 -= invPow2(oldValue)); }
      else               { host.putKxQ1(kxq1 -= invPow2(oldValue)); }
      if (newValue < 32) { host.putKxQ0(kxq0 += invPow2(newValue)); }
      else               { host.putKxQ1(kxq1 += invPow2(newValue)); }
    }
docs: Called here and by Heap and Direct 6 and 8 bit implementations