1.1. Singleton Pattern 1.2. Factory Pattern
- Iterator Pattern
1.1 csharpindepth.com/Articles/General/Singleton.aspx 1.2 http://www.newthinktank.com/2012/09/factory-design-pattern-tutorial/ 2.1 https://msdn.microsoft.com/en-us/library/system.collections.ienumerable(v=vs.110).aspx