docs: public static double quantile(double val, double k, double lambda, double theta) {
      if(val < 0.0 || val > 1.0) {
        return Double.NaN;
      }
      else if(val == 0) {
        return 0.0;
      }
      else if(val == 1) {
        return Double.POSITIVE_INFINITY;
      }
      else {
        return theta + lambda * FastMath.pow(-FastMath.log(1.0 - val), 1.0 / k);
      }
    }