docs: private double epsilon(Front front, Front referenceFront) throws JMetalException {
  
      double eps, epsJ = 0.0, epsK = 0.0, epsTemp;
  
      int numberOfObjectives = front.getPointDimensions() ;
  
      eps = Double.MIN_VALUE;
  
      for (int i = 0; i < referenceFront.getNumberOfPoints(); i++) {
        for (int j = 0; j < front.getNumberOfPoints(); j++) {
          for (int k = 0; k < numberOfObjectives; k++) {
            epsTemp = front.getPoint(j).getValue(k)
                - referenceFront.getPoint(i).getValue(k);
            if (k == 0) {
              epsK = epsTemp;
            } else if (epsK < epsTemp) {
              epsK = epsTemp;
            }
          }
          if (j == 0) {
            epsJ = epsK;
          } else if (epsJ > epsK) {
            epsJ = epsK;
          }
        }
        if (i == 0) {
          eps = epsJ;
        } else if (eps < epsJ) {
          eps = epsJ;
        }
      }
      return eps;
    }