Bring the YAML package's style up to modern standards.

pkg/yaml/lib/src/constructor.dart

 // Copyright (c) 2012, 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 constructor;
+library yaml.constructor;
 
 import 'model.dart';
 import 'visitor.dart';
 import 'yaml_map.dart';
 
 /// Takes a parsed and composed YAML document (what the spec calls the
 /// "representation graph") and creates native Dart objects that represent that
 /// document.
 class Constructor extends Visitor {
   /// The root node of the representation graph.
@@ skipping 35 matching lines @@
     if (_anchors.containsKey(anchored.anchor)) return _anchors[anchored.anchor];
   }
 
   /// Records that [value] is the Dart object representing [anchored].
   setAnchor(Node anchored, value) {
     if (anchored.anchor == null) return value;
     _anchors[anchored.anchor] = value;
     return value;
   }
 }