docs: public double calcAzimuth(Instruction nextI) {
          double nextLat;
          double nextLon;
  
          if (points.getSize() >= 2) {
              nextLat = points.getLatitude(1);
              nextLon = points.getLongitude(1);
          } else if (nextI != null && points.getSize() == 1) {
              nextLat = nextI.points.getLatitude(0);
              nextLon = nextI.points.getLongitude(0);
          } else {
              return Double.NaN;
          }
  
          double lat = points.getLatitude(0);
          double lon = points.getLongitude(0);
          return AC.calcAzimuth(lat, lon, nextLat, nextLon);
      }