anchor.diff:  int? _getCallbackHandle(Function closure) native 'GetCallbackHandle';
   Function? _getCallbackFromHandle(int handle) native 'GetCallbackFromHandle';
   
  -// Required for gen_snapshot to work correctly.
  -int? _isolateId; // ignore: unused_element
  +typedef _PrintClosure = void Function(String line);
   
  +// Used by the embedder to initialize how printing is performed.
  +// See also https://github.com/dart-lang/sdk/blob/main/sdk/lib/_internal/vm/lib/print_patch.dart
   @pragma('vm:entry-point')
  -Function _getPrintClosure() => _print;
  +_PrintClosure _getPrintClosure() => _print;
  +
  +typedef _ScheduleImmediateClosure = void Function(void Function());
  +
  +// Used by the embedder to initialize how microtasks are scheduled.
  +// See also https://github.com/dart-lang/sdk/blob/main/sdk/lib/_internal/vm/lib/schedule_microtask_patch.dart
   @pragma('vm:entry-point')
  -Function _getScheduleMicrotaskClosure() => _scheduleMicrotask;
  +_ScheduleImmediateClosure _getScheduleMicrotaskClosure() => _scheduleMicrotask;
  
positive.code: }
  
  @pragma('vm:entry-point')
  void _setupHooks() {  // ignore: unused_element
    assert(() {
      // In debug mode, register the schedule frame extension.
      developer.registerExtension('ext.ui.window.scheduleFrame', _scheduleFrame);
  
negative.code: // Copyright 2013 The Flutter Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // @dart = 2.12
  part of dart.ui;
  