Lesson 46. 13/27 (9 x 3)

1. Course W-402277:
- generic classes, generic methods, constraints (module 5)
- extensions methods (module 5)
fluent api:
1. http://rlacovara.blogspot.co.il/2009/07/fluent-interface-for-composing-entity.html

2.1.  http://visualstudiomagazine.com/articles/2013/11/01/when-to-build-fluent-interfaces-for-re-use-and-3. clarity.aspx
2.2. http://visualstudiomagazine.com/articles/2014/01/01/strategies-and-code-for-creating-fluent-apis.aspx

3. Threading. Albahari, up to Join and Sleep. Singleton, thread-safety version.