anchor.diff:  /// The function must only access zone-related functionality through
   /// [self], [parent] or [zone].
   /// It should not depend on the current zone ([Zone.current]).
  -typedef void ScheduleMicrotaskHandler(
  -    Zone self, ZoneDelegate parent, Zone zone, void f());
  +typedef ScheduleMicrotaskHandler = void Function(
  +    Zone self, ZoneDelegate parent, Zone zone, void Function() f);
   
   /// The type of a custom [Zone.createTimer] implementation function.
   ///
  
positive.code:   /// import 'dart:async';
    ///
    /// main() {
    ///   runZoned(() {
    ///     // The following asynchronous error is *not* caught by the `catchError`
    ///     // in the nested zone, since errors are not to cross zone boundaries
    ///     // with different error handlers.
    ///     // Instead the error is handled by the current error handler,
    ///     // printing "Caught by outer zone: asynchronous error".
    ///     var future = Future.error("asynchronous error");
    ///     runZoned(() {
    ///       future.catchError((e) { throw "is never reached"; });
    ///     }, onError: (e) { throw "is never reached"; });
    ///   }, onError: (e) { print("Caught by outer zone: $e"); });
    /// }
    /// ```
    Zone get errorZone;
  
negative.code: /// The function must only access zone-related functionality through
  /// [self], [parent] or [zone].
  /// It should not depend on the current zone ([Zone.current]).
  typedef ForkHandler = Zone Function(Zone self, ZoneDelegate parent, Zone zone,
      ZoneSpecification? specification, Map<Object?, Object?>? zoneValues);
  
  class _ZoneFunction<T extends Function> {
  