Create an apptesting framework for dart.

third_party/dart-packages/stack_trace/stack_trace/src/lazy_trace.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 lazy_trace;
 
 import 'frame.dart';
 import 'trace.dart';
 
 /// A thunk for lazily constructing a [Trace].
 typedef Trace TraceThunk();
 
 /// A wrapper around a [TraceThunk]. This works around issue 9579 by avoiding
 /// the conversion of native [StackTrace]s to strings until it's absolutely
 /// necessary.
 class LazyTrace implements Trace {
   final TraceThunk _thunk;
   Trace _inner;
 
   LazyTrace(this._thunk);
 
   Trace get _trace {
     if (_inner == null) _inner = _thunk();
     return _inner;
   }
 
   List<Frame> get frames => _trace.frames;
   StackTrace get vmTrace => _trace.vmTrace;
   Trace get terse => new LazyTrace(() => _trace.terse);
-  Trace foldFrames(bool predicate(frame)) =>
-    new LazyTrace(() => _trace.foldFrames(predicate));
+  Trace foldFrames(bool predicate(frame), {bool terse: false}) =>
+    new LazyTrace(() => _trace.foldFrames(predicate, terse: terse));
   String toString() => _trace.toString();
 
   // Work around issue 14075.
   set frames(_) => throw new UnimplementedError();
 }