Index signature to get the text track at the requested index in the list.
Add the given listener for the given event type(s).
The type of the event.
The callback which is executed when the event occurs.
Return the text track at the requested index in the list.
A number
representing the index of a text track in the list.
The text track with index index
in the list.
Remove the given listener for the given event type(s).
The type of the event.
The callback which will be removed.
List of text tracks.