mapSync method
Transforms the inner Sync instance if this is a Sync.
Provided for pair-axis symmetry with Result.mapOk/Result.mapErr — real code almost always wants resultMap, fold, or foldResult instead, since those operate on the inner Result where the meaningful payload lives.
Implementation
@override
@visibleForTesting
@pragma('vm:prefer-inline')
Async<T> mapSync(@noFutures Sync<T> Function(Sync<T> sync) noFutures) {
return this;
}