extends the decorator1x0 interface by adding layer ability.
Decorator2x0 should be used for decorating complex object structures which are connected with bridge design pattern
and must be decentralized decorated without using global synchronization structure.
I used this design pattern first time in the RedBlackTree implementation of the happy-collection 2010.
For example if the Tree and the TreeNode must be decorated then both decorators must work together.
For example if I give a TreeNode to a method of the Tree, then this method has to find correct decorator of the TreeNode to get needed information from it.
Another method could be to use a global structure, where all nodes could be stored and gated, but it would be to slow!
The Method of Decorator2x0 is simple the Tree would search for the decorator with the same LayerNumber and then use the found TreeNode!
first decorator has the layer number = 0, the flowing decorator should have a bigger layerNumber!