internal void Add(INodeViewCustomizations cs)
        {
            var custs = cs.GetCustomizations();

            foreach (var pair in custs)
            {
                var nodeModelType = pair.Key;
                var custTypes     = pair.Value;

                foreach (var custType in custTypes)
                {
                    this.Add(nodeModelType, InternalNodeViewCustomization.Create(nodeModelType, custType));
                }
            }
        }