docs: public static double bearingRad(double latS, double lngS, double latE, double lngE) {
      final DoubleWrapper tmp = new DoubleWrapper(); // To return cosine
      final double slatS = sinAndCos(latS, tmp), clatS = tmp.value;
      final double slatE = sinAndCos(latE, tmp), clatE = tmp.value;
      return atan2(-sin(lngS - lngE) * clatE, clatS * slatE - slatS * clatE * cos(lngS - lngE));
    }