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ExtendableEvent: ExtendableEvent() constructor - Web APIs | MDN
ExtendableEvent: ExtendableEvent() constructor Baseline Widely available
The ExtendableEvent()ExtendableEvent
new ExtendableEvent(type)
new ExtendableEvent(type, options)
type
A string with the name of the event. It is case-sensitive.
options Optional
An object that, in addition of the properties defined in Event() , can contain any custom settings
that you want to apply to the event object.
Currently no possible options are mandatory,
but this has been defined for forward compatibility across the different derived events.
