private void Pack(Solver cp, IntVar[] binvars, int[] weights, IntVar[] loadvars)
        {
            IntVar[] b = new IntVar[binvars.Length];

            for(long j=0; j<loadvars.Length; j++)
            {
                for (int i = 0; i < binvars.Length; i++)
                {
                    b[i] = cp.MakeIsEqualCstVar(binvars[i], j);
                }
                cp.Add(cp.MakeScalProd(b, weights) == loadvars[j]);
            }
            
            cp.Add(cp.MakeSumEquality(loadvars, cp.MakeIntVar(weights.Sum(), weights.Sum(), "Sum")));
        }