docs: public static double cdf(double x, double mu, double sigma, double lambda) {
      if(x == Double.NEGATIVE_INFINITY) {
        return 0.;
      }
      if(x == Double.POSITIVE_INFINITY) {
        return 1.;
      }
      final double u = lambda * (x - mu);
      final double v = lambda * sigma;
      final double v2 = v * v;
      final double logphi = FastMath.log(NormalDistribution.cdf(u, v2, v));
      return NormalDistribution.cdf(u, 0., v) - FastMath.exp(-u + v2 * .5 + logphi);
    }