About TWIN : ---
Twin pattern is a design pattern which provides a standard solution to simulate multiple
inheritance in java
![alt text](./etc/twin.png "Twin")
Use the Twin idiom when
* to simulate multiple inheritance in a language that does not support this feature.
* to avoid certain problems of multiple inheritance such as name clashes.
* [Twin – A Design Pattern for Modeling Multiple Inheritance](http://www.ssw.uni-linz.ac.at/Research/Papers/Moe99/Paper.pdf)