if (collectionViewGroup.IsBottomLevel)
                CalcColumnSums(collectionViewGroup);
            else
            {
                foreach (CollectionViewGroup coll2 in collectionViewGroup.Items)
                {
                    if (coll2.IsBottomLevel)
                    {
                        CalcColumnSums(coll2);
                    }
                    else
                    {
                        foreach (CollectionViewGroup coll3 in coll2.Items)
                        {
                            if (coll3.IsBottomLevel)
                            {
                                CalcColumnSums(coll3);
                            }
                            else
                            {
                                foreach (CollectionViewGroup coll4 in coll3.Items)
                                {
                                    if (coll4.IsBottomLevel)
                                    {
                                        CalcColumnSums(coll4);
                                    }
                                }
                            }
                        }
                    }
                }
            }