Make isEmpty a getter.

utils/pub/pub.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.
 
 /**
  * The main entrypoint for the pub command line application.
  */
 library pub;
 
 import '../../pkg/args/lib/args.dart';
@@ skipping 50 matching lines @@
   } on FormatException catch (e) {
     printUsage(description: e.message);
     return;
   }
 
   if (globalOptions['version']) {
     printVersion();
     return;
   }
 
-  if (globalOptions['help'] || globalOptions.rest.isEmpty()) {
+  if (globalOptions['help'] || globalOptions.rest.isEmpty) {
     printUsage();
     return;
   }
 
   // TODO(nweiz): Have a fallback for this this out automatically once 1145 is
   // fixed.
   var sdkDir = Platform.environment['DART_SDK'];
   var cacheDir;
   if (Platform.environment.containsKey('PUB_CACHE')) {
     cacheDir = Platform.environment['PUB_CACHE'];
@@ skipping 166 matching lines @@
   abstract Future onRun();
 
   /** Displays usage information for this command. */
   void printUsage([String description]) {
     if (description == null) description = this.description;
     print(description);
     print('');
     print('Usage: $usage');
 
     var commandUsage = commandParser.getUsage();
-    if (!commandUsage.isEmpty()) {
+    if (!commandUsage.isEmpty) {
       print('');
       print(commandUsage);
     }
   }
 
   /// Returns the appropriate exit code for [exception], falling back on 1 if no
   /// appropriate exit code could be found.
   int _chooseExitCode(exception) {
     if (exception is HttpException || exception is HttpParserException ||
         exception is SocketIOException || exception is PubHttpException) {
       return exit_codes.UNAVAILABLE;
     } else if (exception is FormatException) {
       return exit_codes.DATA;
     } else {
       return 1;
     }
   }
 }