public void Weights_WrongValues(double d1, double d2, double d3)
        {
            var w = new List <double> {
                d1, d2, d3
            };

            Assert.False(CategoricalDistribution.IsValidParam(w));
            Assert.False(Dist.AreValidWeights(w));
            Assert.Throws <ArgumentOutOfRangeException>(() => { Dist.Weights = w; });
        }