Make hashCode a getter and not a method.

runtime/bin/socket.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.
 
 abstract class ServerSocket {
   /**
    * Constructs a new server socket, binds it to a given address and port,
    * and listens on it.
    */
   factory ServerSocket(String bindAddress, int port, int backlog) {
@@ skipping 110 matching lines @@
   String get remoteHost;
 
   /**
    * Closes the socket. Calling [close] will never throw an exception
    * and calling it several times is supported. If [halfClose] is true
    * the socket will only be closed for writing and it might still be
    * possible to read data. Calling [close] will not trigger a call to
    * [onClosed].
    */
   void close([bool halfClose = false]);
-
-  /**
-   * Socket is hashable.
-   */
-  int hashCode();
 }
 
 
 class SocketIOException implements Exception {
   const SocketIOException([String this.message = "",
                            OSError this.osError = null]);
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.add("SocketIOException");
     if (!message.isEmpty()) {
       sb.add(": $message");
       if (osError != null) {
         sb.add(" ($osError)");
       }
     } else if (osError != null) {
       sb.add(": $osError");
     }
     return sb.toString();
   }
   final String message;
   final OSError osError;
 }