pkg: analysis aided cleanup

pkg/http/lib/src/mock_client.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 mock_client;
 
 import 'dart:async';
-import 'dart:io';
 
 import 'base_client.dart';
 import 'base_request.dart';
 import 'byte_stream.dart';
 import 'request.dart';
 import 'response.dart';
 import 'streamed_response.dart';
 import 'utils.dart';
 
 // TODO(nweiz): once Dart has some sort of Rack- or WSGI-like standard for
@@ skipping 62 matching lines @@
 }
 
 /// A handler function that receives [StreamedRequest]s and sends
 /// [StreamedResponse]s. Note that [request] will be finalized.
 typedef Future<StreamedResponse> MockClientStreamHandler(
     BaseRequest request, ByteStream bodyStream);
 
 /// A handler function that receives [Request]s and sends [Response]s. Note that
 /// [request] will be finalized.
 typedef Future<Response> MockClientHandler(Request request);