private void buildCalculationMethodCombinationTree(string compoundName, CalculationMethodCache configurationCache, TreeItem <CalculationMethodWithCompoundName> treeRoot)
        {
            var categoryCache = new Cache <string, IEnumerable <CalculationMethodWithCompoundName> >();

            configurationCache.GroupBy(method => method.Category).Each(grouping =>
            {
                categoryCache[grouping.Key] = grouping.Select(method => new CalculationMethodWithCompoundName(method, compoundName)).ToList();
            });

            categoryCache.Keys.Each(key => treeRoot.AddToAllLeaves(categoryCache[key]));
        }