SharedBag

A shared bag is a collection of key and values, which implements a monostate pattern, i.e. there is only one bag, which can be accessed though an arbitrary amount of SharedBag instances.

The SharedBag class can be used as: — shared context, to contain the application configuration — service locator, to contain application dependencies — a migration path to store global variables of a legacy application pending the migration to a collection sharing the same interface

Such patterns can be discouraged and as such used with architectural care, as they mainly use SharedBag as global variables, or as an antipattern.