code: private static double limitHprime(double hPrime) {
          hPrime /= 360.0;
          final double limited = 360.0 * (hPrime - floor(hPrime));
  
          if (limited < -180.0) {
              return limited + 360.0;
          } else if (limited > 180.0) {
              return limited - 360.0;
          } else {
              return limited;
          }
      }
docs: limit H' values according to A.2.11