System.Configuration.ConfigurationElement.IntersectLockCollections C# (CSharp) Метод

        private StringCollection IntersectLockCollections(ConfigurationLockCollection Collection1, ConfigurationLockCollection Collection2) {
            ConfigurationLockCollection smallCollection = Collection1.Count < Collection2.Count ? Collection1 : Collection2;
            ConfigurationLockCollection largeCollection = Collection1.Count >= Collection2.Count ? Collection1 : Collection2;
            StringCollection intersectionCollection = new StringCollection();

            foreach (string key in smallCollection) {
                if (largeCollection.Contains(key) || key == ElementTagName)
                    intersectionCollection.Add(key);  // add the local copy
            }
            return intersectionCollection;
        }