Accord.Math.Optimization.QuadraticObjectiveFunction.addTuple C# (CSharp) Метод

        private static Tuple<string, string> addTuple(Dictionary<Tuple<string, string>,
            double> terms, double v, string v1, string v2)
        {

            var t1 = Tuple.Create(v1, v2);
            var t2 = Tuple.Create(v2, v1);

            if (!terms.ContainsKey(t1) && !terms.ContainsKey(t2))
                terms[t1] = v;
            return t1;
        }