anchor.diff:  
   import 'common.dart';
   export 'common.dart' show PackedRequest;
  +import 'client_backend.dart';
   
   /**
    * Type of handler which can be registered in [MultiRequestHandler] for
  
positive.code:              (PackedRequest request) {
                 // Create new server request from packed request and add
                 // authenticatedUserId to it
                   ServerRequest serverRequest = new ServerRequest(request.clientRequest.type,
                                                                   request.clientRequest.args,
                                                                   authenticatedUserId);
                   
                   _handleClientRequest(serverRequest).then(
                       (response) {
  
negative.code:   final dynamic args;
    final String type;
    String authenticatedUserId;
    Connection loopback;
  
    /**
     * Creates a [ServerRequest] with specified [type] and [args]
     * [type] is the name of the requested server function
     * [args] is a map of arguments for the specified server function
     */
    ServerRequest(this.type, this.args, this.authenticatedUserId, this.loopback);
  }
  
  
  