Factory Pattern

[wsdt]

Avoid using Singletons, maybe change to Factory Pattern (if an alternative is needed):

• https://www.tutorialspoint.com/design_pattern/factory_pattern.htm
• https://testing.googleblog.com/2008/08/where-have-all-singletons-gone.html

1 Factory can consist of many classes with a similar lifetime (e.g. level-dependent, etc.) --> so group singleton-like classes into a factory which get's instantiated.

[wsdt]

Transformed Mgrs' methods/members to static and made all constructors private, so NO INSTANCE can be created.

If an instance is necessary, use Factory pattern and not singleton.