Make isEmpty a getter.

samples/buildhook2/build.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.
 
 import "dart:io";
 import "package:args/args.dart";
 
 bool cleanBuild;
 bool fullBuild;
 List<String> changedFiles;
@@ skipping 36 matching lines @@
   parser.addFlag("help", negatable: false, help: "displays this help and exit");
   var args = parser.parse(new Options().arguments);
   if (args["help"]) {
     print(parser.getUsage());
     exit(0);
   }
 
   changedFiles = args["changed"];
   removedFiles = args["removed"];
   cleanBuild = args["clean"];
-  fullBuild = changedFiles.isEmpty() && removedFiles.isEmpty() && !cleanBuild;
+  fullBuild = changedFiles.isEmpty && removedFiles.isEmpty && !cleanBuild;
 }
 
 /**
  * Delete all generated files.
  */
 void handleCleanCommand() {
   Directory current = new Directory.current();
   current.list(recursive: true).onFile = _maybeClean;
 }
 
@@ skipping 47 matching lines @@
 }
 
 /**
  * If this file is a generated file (based on the extension), delete it.
  */
 void _maybeClean(String file) {
   if (file.endsWith(".foobar")) {
     new File(file).delete();
   }
 }