Description:

The App class owns an instance of Controller.  The App class also has a Boot() method, as well as a Shutdown() method.

The Controller is defined thus:

The CmdInvoker class needs special documentation, because it uses a little bit of Python "magic" to work.

When you call any method on an instance of this invoker class, the method is interpreted as the name of a command class to be instantiated. Parameters in the method call are used as parameters to the constructor. After the command class is instantiated, a context object is attached, and the command passed to a command manager to be run. No extra parameters are injected into the constructor or to the execute() call.