How to use the @iiif/vocabulary.MediaType.M3U8 function in @iiif/vocabulary

load: this._extensions[Extension.AV]
        };

        this._extensionRegistry[MediaType.WEBM] = {
            load: this._extensions[Extension.AV]
        };

        this._extensionRegistry[MediaType.THREEJS] = {
            load: this._extensions[Extension.VIRTEX]
        };

        this._extensionRegistry[MediaType.MP3] = {
            load: this._extensions[Extension.AV]
        };

        this._extensionRegistry[MediaType.M3U8] = {
            load: this._extensions[Extension.AV]
        };

        this._extensionRegistry[MediaType.MPEG_DASH] = {
            load: this._extensions[Extension.AV]
        };

        this._extensionRegistry["av"] = {
            load: this._extensions[Extension.AV]
        };

        this._extensionRegistry["default"] = {
            load: this._extensions[Extension.DEFAULT]
        };

        this.set(this.options.data);