Clean up wording of client usage expectations

pkg/analysis_server/lib/plugin/protocol/protocol.dart

 // Copyright (c) 2014, 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.
 
 /**
  * Support for client code that needs to interact with the requests, responses
  * and notifications that are part of the analysis server's wire protocol.
  */
 library analysis_server.plugin.protocol.protocol;
 
 import 'dart:collection';
 import 'dart:convert' hide JsonDecoder;
 
 import 'package:analysis_server/src/protocol/protocol_internal.dart';
 
 part 'generated_protocol.dart';
 
 /**
  * A [RequestHandler] that supports [startup] and [shutdown] methods.
  *
- * Clients are not expected to subtype this class.
+ * Clients may not extend, implement or mix-in this class.
  */
 abstract class DomainHandler extends RequestHandler {
   /**
    * Perform any operations associated with the shutdown of the domain. It is
    * not guaranteed that this method will be called. If it is, it will be
    * called after the last [Request] has been made.
    */
   void shutdown() {}
 
   /**
    * Perform any operations associated with the startup of the domain. This
    * will be called before the first [Request].
    */
   void startup() {}
 }
 
 /**
  * An interface for enumerated types in the protocol.
  *
- * Clients are not expected to subtype this class.
+ * Clients may not extend, implement or mix-in this class.
  */
 abstract class Enum {
   /**
    * The name of the enumerated value. This should match the name of the
    * static getter which provides access to this enumerated value.
    */
   String get name;
 }
 
 /**
  * A notification from the server about an event that occurred.
  *
- * Clients are not expected to subtype this class.
+ * Clients may not extend, implement or mix-in this class.
  */
 class Notification {
   /**
    * The name of the JSON attribute containing the name of the event that
    * triggered the notification.
    */
   static const String EVENT = 'event';
 
   /**
    * The name of the JSON attribute containing the result values.
@@ skipping 36 matching lines @@
     if (_params != null) {
       jsonObject[PARAMS] = _params;
     }
     return jsonObject;
   }
 }
 
 /**
  * A request that was received from the client.
  *
- * Clients are not expected to subtype this class.
+ * Clients may not extend, implement or mix-in this class.
  */
 class Request {
   /**
    * The name of the JSON attribute containing the id of the request.
    */
   static const String ID = 'id';
 
   /**
    * The name of the JSON attribute containing the name of the request.
    */
@@ skipping 125 matching lines @@
       jsonObject[CLIENT_REQUEST_TIME] = clientRequestTime;
     }
     return jsonObject;
   }
 }
 
 /**
  * An exception that occurred during the handling of a request that requires
  * that an error be returned to the client.
  *
- * Clients are not expected to subtype this class.
+ * Clients may not extend, implement or mix-in this class.
  */
 class RequestFailure implements Exception {
   /**
    * The response to be returned as a result of the failure.
    */
   final Response response;
 
   /**
    * Initialize a newly created exception to return the given reponse.
    */
   RequestFailure(this.response);
 }
 
 /**
  * An object that can handle requests and produce responses for them.
  *
- * Clients are not expected to subtype this class.
+ * Clients may not extend, implement or mix-in this class.
  */
 abstract class RequestHandler {
   /**
    * Attempt to handle the given [request]. If the request is not recognized by
    * this handler, return `null` so that other handlers will be given a chance
    * to handle it. Otherwise, return the response that should be passed back to
    * the client.
    */
   Response handleRequest(Request request);
 }
 
 /**
  * A response to a request.
  *
- * Clients are not expected to subtype this class.
+ * Clients may not extend, implement or mix-in this class.
  */
 class Response {
   /**
    * The [Response] instance that is returned when a real [Response] cannot
    * be provided at the moment.
    */
   static final Response DELAYED_RESPONSE = new Response('DELAYED_RESPONSE');
 
   /**
    * The name of the JSON attribute containing the id of the request for which
@@ skipping 256 matching lines @@
     jsonObject[ID] = id;
     if (error != null) {
       jsonObject[ERROR] = error.toJson();
     }
     if (_result != null) {
       jsonObject[RESULT] = _result;
     }
     return jsonObject;
   }
 }