Make hashCode a getter and not a method.

utils/pub/yaml/model.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.
 
 // This file contains the node classes for the internal representations of YAML
 // documents. These nodes are used for both the serialization tree and the
 // representation graph.
 
 /** A tag that indicates the type of a YAML node. */
 class _Tag {
@@ skipping 28 matching lines @@
   }
 
   String toString() {
     if (name.startsWith(YAML_URI_PREFIX)) {
       return '!!${name.substring(YAML_URI_PREFIX.length)}';
     } else {
       return '!<$name>';
     }
   }
 
-  int hashCode() => name.hashCode();
+  int get hashCode => name.hashCode;
 }
 
 /** The abstract class for YAML nodes. */
 class _Node {
   /** Every YAML node has a tag that describes its type. */
   _Tag tag;
 
   /** Any YAML node can have an anchor associated with it. */
   String anchor;
 
   _Node(this.tag, [this.anchor]);
 
   bool operator ==(other) {
     if (other is! _Node) return false;
     return tag == other.tag;
   }
 
-  int hashCode() => _hashCode([tag, anchor]);
+  int get hashCode => _hashCode([tag, anchor]);
 
   abstract visit(_Visitor v);
 }
 
 /** A sequence node represents an ordered list of nodes. */
 class _SequenceNode extends _Node {
   /** The nodes in the sequence. */
   List<_Node> content;
 
   _SequenceNode(String tagName, this.content)
     : super(new _Tag.sequence(tagName));
 
   /** Two sequences are equal if their tags and contents are equal. */
   bool operator ==(other) {
     // Should be super != other; bug 2554
     if (!(super == other) || other is! _SequenceNode) return false;
     if (content.length != other.content.length) return false;
     for (var i = 0; i < content.length; i++) {
       if (content[i] != other.content[i]) return false;
     }
     return true;
   }
 
   String toString() => '$tag [${Strings.join(content.map((e) => '$e'), ', ')}]';
 
-  int hashCode() => super.hashCode() ^ _hashCode(content);
+  int get hashCode => super.hashCode ^ _hashCode(content);
 
   visit(_Visitor v) => v.visitSequence(this);
 }
 
 /** An alias node is a reference to an anchor. */
 class _AliasNode extends _Node {
   _AliasNode(String anchor) : super(new _Tag.scalar(_Tag.yaml("str")), anchor);
 
   visit(_Visitor v) => v.visitAlias(this);
 }
@@ skipping 90 matching lines @@
    * Left-pads [str] with zeros so that it's at least [length] characters
    * long.
    */
   String zeroPad(String str, int length) {
     assert(length >= str.length);
     var prefix = [];
     prefix.insertRange(0, length - str.length, '0');
     return '${Strings.join(prefix, '')}$str';
   }
 
-  int hashCode() => super.hashCode() ^ content.hashCode();
+  int get hashCode => super.hashCode ^ content.hashCode;
 
   visit(_Visitor v) => v.visitScalar(this);
 }
 
 /** A mapping node represents an unordered map of nodes to nodes. */
 class _MappingNode extends _Node {
   /** The node map. */
   Map<_Node, _Node> content;
 
   _MappingNode(String tagName, this.content)
@@ skipping 10 matching lines @@
     }
     return true;
   }
 
   String toString() {
     var strContent = Strings.join(content.getKeys().
         map((k) => '${k}: ${content[k]}'), ', ');
     return '$tag {$strContent}';
   }
 
-  int hashCode() => super.hashCode() ^ _hashCode(content);
+  int get hashCode => super.hashCode ^ _hashCode(content);
 
   visit(_Visitor v) => v.visitMapping(this);
 }