Change other futures to also have timeout take a named parameter.

pkg/scheduled_test/lib/src/value_future.dart

Index: pkg/scheduled_test/lib/src/value_future.dart
diff --git a/pkg/scheduled_test/lib/src/value_future.dart b/pkg/scheduled_test/lib/src/value_future.dart
index 3821feb674369d8a6a82ee13407017e09969f771..b0d458b9df90dd1cabd92a17ba7eb96366392298 100644
--- a/pkg/scheduled_test/lib/src/value_future.dart
+++ b/pkg/scheduled_test/lib/src/value_future.dart
@@ -35,6 +35,6 @@ class ValueFuture<T> implements Future<T> {
   Future then(onValue(T value), {Function onError}) =>
     _future.then(onValue, onError: onError);
   Future<T> whenComplete(action()) => _future.whenComplete(action);
-  Future timeout(Duration timeLimit, [void onTimeout()]) =>
-    _future.timeout(timeLimit, onTimeout);
+  Future timeout(Duration timeLimit, {void onTimeout()}) =>
+    _future.timeout(timeLimit, onTimeout: onTimeout);
 }