Determines if the Control or one of its children can consume the request.
Determines if the Control can take the initiative.
Gets the Control's state as an object that is serializable.
Framework behavior:
JSON.stringify(obj)
Handles the request.
TODO
Sets the state from a serialized state object
Takes the initiative by adding an InitiativeAct to the result.
Defines a Control that has child controls.
This is the minimal definition required by the Runtime (ControlHandler) See
ContainerControl
for the actual class used by Control implementations.