pkg: analysis aided cleanup

pkg/scheduled_test/lib/src/descriptor/async_descriptor.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library descriptor.async;
 
 import 'dart:async';
-import 'dart:io' as io;
 
 import '../../descriptor.dart';
 import '../../scheduled_test.dart';
-import '../utils.dart';
 
 /// A descriptor that wraps a [Future<Descriptor>] and forwards all asynchronous
 /// operations to the result of the future. It's designed for use when the full
 /// filesystem description isn't known when initializing the schedule.
 ///
 /// [AsyncDescriptor]s don't support [load], since their names aren't
 /// synchronously available.
 class AsyncDescriptor extends Descriptor {
   /// The [Future] that will complete to the [Descriptor] this descriptor is
   /// wrapping.
   final Future<Descriptor> future;
 
   AsyncDescriptor(this.future)
       : super('<async descriptor>');
 
   Future create([String parent]) =>
     schedule(() => future.then((entry) => entry.create(parent)));
 
   Future validate([String parent]) => schedule(() => validateNow(parent));
 
   Future validateNow([String parent]) =>
     future.then((entry) => entry.validateNow(parent));
 
   String describe() => "async descriptor";
 }