Refactor removeRange.

samples/third_party/todomvc/web/model.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 model;
 
 import 'package:web_ui/observe.dart';
 import 'package:web_ui/observe/html.dart';
 
 @observable
@@ skipping 11 matching lines @@
 // The real model:
 
 @observable
 class AppModel {
   ObservableList<Todo> todos = new ObservableList<Todo>();
 
   // TODO(jmesserly): remove this once List has a remove method.
   void removeTodo(Todo todo) {
     var index = todos.indexOf(todo);
     if (index != -1) {
-      todos.removeRange(index, 1);
+      todos.removeRange(index, index + 1);
     }
   }
 
   bool get allChecked => todos.length > 0 && todos.every((t) => t.done);
 
   set allChecked(bool value) => todos.forEach((t) { t.done = value; });
 
   int get doneCount {
     int res = 0;
     todos.forEach((t) { if (t.done) res++; });
@@ skipping 12 matching lines @@
 
 @observable
 class Todo {
   String task;
   bool done = false;
 
   Todo(this.task);
 
   String toString() => "$task ${done ? '(done)' : '(not done)'}";
 }