Oop singleton

https://testing.googleblog.com/2008/08/root-cause-of-singletons.html , http://misko.hevery.com/2008/08/17/singletons-are-pathological-liars/ , http://misko.hevery.com/2008/08/21/where-have-all-the-singletons-gone/

https://matt.berther.io/

https://blogs.msdn.microsoft.com/scottdensmore/2004/05/25/why-singletons-are-evil/

http://www.davidtanzer.net/6_reasons_why_you_should_avoid_singletons

links
Oop