Change generic comment syntax to real generic syntax.

lib/src/typed/future.dart

Index: lib/src/typed/future.dart
diff --git a/lib/src/typed/future.dart b/lib/src/typed/future.dart
index 995f4b5ca4fe9d33a8c0a36cacd06bb66cf50c31..8534753ae366e7ac37712e98bf039b5c1ee14390 100644
--- a/lib/src/typed/future.dart
+++ b/lib/src/typed/future.dart
@@ -14,8 +14,8 @@ class TypeSafeFuture<T> implements Future<T> {
   Future<T> catchError(Function onError, {bool test(Object error)}) async =>
       new TypeSafeFuture<T>(_future.catchError(onError, test: test));
 
-  Future/*<S>*/ then/*<S>*/(dynamic onValue(T value), {Function onError}) =>
-      _future.then((value) => onValue(value as T), onError: onError);
+  Future<S> then<S>(dynamic onValue(T value), {Function onError}) => _future
+      .then((value) => onValue(value as T), onError: onError);
 
   Future<T> whenComplete(action()) =>
       new TypeSafeFuture<T>(_future.whenComplete(action));