Question from the Symfony 3 test

An Event object is not required to dispatch an event by the "dispatch" method of the EventDispatcher, only the name of the event is required.

The ContainerAwareEventDispatcher is an implementation of the EventDispatcher that allows lazy loading of services declared as event listeners.

The stopPropagation() method of the Event class allows to block the propagation of all other events of the EventDispatcher.

The "kernel.terminate" event is unique and it is the last propagated because it is dispatched after the HttpKernel::handle() method and after the Response is sent to the client.