The ready state of a text track, represented by a value from the following list:
0: Indicates that the text track's cues have not been obtained.
1: The text track is loading. Further cues might still be added to the track by the parser.
2: The text track has been loaded with no fatal errors.
3: An error occurred obtaining the cues for the track. Some or all of the cues are likely missing and will not be obtained.
export declare type TextTrackReadyState = 0 | 1 | 2 | 3;