Various cleanup

lib/src/transformer/asset_source.dart

 // Copyright (c) 2016, 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.
 
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart' show Source, UriKind;
 import 'package:barback/barback.dart' show Asset, TimestampedData;
 import 'package:path/path.dart' as path;
 
 class AssetSource implements Source {
   final Uri uri;
   final Asset asset;
   final String contentString;
   AssetSource(this.uri, this.asset, this.contentString);
 
-  @override toString() => 'AssetSource($uri, ${asset.id})';
+  @override
+  toString() => 'AssetSource($uri, ${asset.id})';
 
   @override
   TimestampedData<String> get contents =>
       new TimestampedData(modificationStamp, contentString);
 
   @override
   String get encoding => null;
 
   @override
   bool exists() => true;
@@ skipping 29 matching lines @@
         return UriKind.DART_URI;
 
       case 'file':
         return UriKind.FILE_URI;
 
       default:
         throw new StateError(uri.toString());
     }
   }
 }