Break some lines to make debugging easier.

sky/sdk/lib/widgets/widget.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:mirrors';
 import 'dart:sky' as sky;
 
 import '../app/view.dart';
@@ skipping 106 matching lines @@
     }
 
     if (node == null) {
       // the child in this slot has gone away
       assert(oldNode.mounted);
       removeChild(oldNode);
       assert(!oldNode.mounted);
       return null;
     }
 
-    if (oldNode != null && oldNode.runtimeType == node.runtimeType && node.key == oldNode.key && node._retainStatefulNodeIfPossible(oldNode)) {
+    if (oldNode != null &&
+        oldNode.runtimeType == node.runtimeType &&
+        oldNode.key == node.key &&
+        node._retainStatefulNodeIfPossible(oldNode)) {
       assert(oldNode.mounted);
       assert(!node.mounted);
       oldNode._sync(node, slot);
       assert(oldNode.root is RenderObject);
       return oldNode;
     }
 
-    if (oldNode != null && (oldNode.runtimeType != node.runtimeType || node.key != oldNode.key)) {
+    if (oldNode != null &&
+        (oldNode.runtimeType != node.runtimeType || oldNode.key != node.key)) {
       assert(oldNode.mounted);
       removeChild(oldNode);
       oldNode = null;
     }
 
     assert(!node.mounted);
     node.setParent(this);
     node._sync(oldNode, slot);
     assert(node.root is RenderObject);
     return node;
@@ skipping 689 matching lines @@
     if (root.parent == null) {
       // we haven't attached it yet
       assert(_container.child == null);
       _container.child = root;
     }
     assert(root.parent == _container);
   }
 
   Widget build() => builder();
 }