public void RegisterMutableAction(Type type, IMutableElement mutableElement)
		{
			if (Mutables.ContainsKey(type))
			{
				Mutables[type] = mutableElement;
			}
			else
			{
				Mutables.Add(type,
					mutableElement);
			}
		}
		public IMutableElement GetMutableAction(Type type)
		{
			return Mutables.ContainsKey(type)
				? Mutables[type]
				: null;
		}