Defines the number of seconds before the scheduled start point when the event should receive the preload call.

Set by the player to the current playback time in seconds, after the current event begins preloading. Defaults to -1 if the event did not start preloading.

If this parameter is greater than 0, then the event will be retriggered by the MediaPlayer after the specific time interval (in seconds).

Defines the maximum number of seconds the event is allowed to live once it has been pretriggered, without setting the loaded property to true.

This dictionary defines all URLs that need to be notified of specific events from the object's lifecycle. The keys are event constants, as defined in MediaPlayer