The `Connections` class manages a list of named configurations that connect to external
resources. Connections are usually comprised of a type (i.e. `'database'` or `'http'`), a
reference to an adapter class (i.e. `'MySql'` or `'CouchDb'`), and authentication credentials.
While connections can be added and removed dynamically during the course of your application
(using `Connections::add()`), it is most typical to define all connections at once, in
The `Connections` class handles adapter classes efficiently by only loading adapter classes and
creating instances when they are requested (using `Connections::get()`).
Adapters are usually subclasses of `lithium\data\Source`.