docs: public static double Canberra(double x1, double y1, double x2, double y2) {
          double distance;
  
          distance = Math.abs(x1 - x2) / (Math.abs(x1) + Math.abs(x2));
          distance += Math.abs(y1 - y2) / (Math.abs(y1) + Math.abs(y2));
  
          return distance;
      }