/**
* Applications do not normally create event instances. They register (and
* unregister) event listener functions, which, when called by the library as
* the result of an event being dispatched, are passed event instances as their
* first argument. Listeners can be registered and unregistered on all objects
* descending from {@link ol.Observable}. All event instances have a `target`
* property, which corresponds to the object on which the event was dispatched.
* By default, `this` within the listener also refers to the target, though
* this can be configured in the listener registration function.
* Some classes have their own event type, which return additional
* properties; see the specific event class page for details.
*
* @namespace ol.events
*/
/**
* @namespace ol.events.condition
*/
OpenLayers 3