Make pub strong-mode clean.

test/pub_uploader_test.dart

 // Copyright (c) 2013, 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.
 
 import 'dart:convert';
 
 import 'package:pub/src/exit_codes.dart' as exit_codes;
 import 'package:pub/src/utils.dart';
 import 'package:scheduled_test/scheduled_process.dart';
 import 'package:scheduled_test/scheduled_server.dart';
@@ skipping 14 matching lines @@
     --package    The package whose uploaders will be modified.
                  (defaults to the current package)
 
 Run "pub help" to see global options.
 See http://dartlang.org/tools/pub/cmd/pub-uploader.html for detailed documentation.
 ''';
 
 ScheduledProcess startPubUploader(ScheduledServer server, List<String> args) {
   var tokenEndpoint = server.url.then((url) =>
       url.resolve('/token').toString());
-  args = flatten(['uploader', '--server', tokenEndpoint, args]);
+  args = ['uploader', '--server', tokenEndpoint]..addAll(args);
   return startPub(args: args, tokenEndpoint: tokenEndpoint);
 }
 
 main() {
   group('displays usage', () {
     integration('when run with no arguments', () {
       schedulePub(args: ['uploader'],
           output: USAGE_STRING, exitCode: exit_codes.USAGE);
     });
 
@@ skipping 111 matching lines @@
 
     server.handle('DELETE', '/api/packages/pkg/uploaders/email',
         (request) => new shelf.Response.ok("{not json"));
 
     pub.stderr.expect(emitsLines(
         'Invalid server response:\n'
         '{not json'));
     pub.shouldExit(1);
   });
 }