anchor.diff:  ///  * https://www.w3.org/TR/webcodecs/#imagedecoderinit-interface
   @JS()
   @anonymous
  +@staticInterop
   class ImageDecoderOptions {
     external factory ImageDecoderOptions({
       required String type,
  
positive.code: ///  * https://www.w3.org/TR/webcodecs/#dictdef-imagedecodeoptions
  @JS()
  @anonymous
  class DecodeOptions {
    external factory DecodeOptions({
      required int frameIndex,
  
negative.code: /// [Future] API.
  @JS()
  @anonymous
  @staticInterop
  class JsPromise {}
  
  /// Corresponds to the browser's `ImageDecoder` type.
  