Make isEmpty a getter.

runtime/bin/file.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.
 
 
 /**
  * FileMode describes the modes in which a file can be opened.
  */
 class FileMode {
   static const READ = const FileMode._internal(0);
@@ skipping 356 matching lines @@
   String get name;
 }
 
 
 class FileIOException implements Exception {
   const FileIOException([String this.message = "",
                          OSError this.osError = null]);
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.add("FileIOException");
-    if (!message.isEmpty()) {
+    if (!message.isEmpty) {
       sb.add(": $message");
       if (osError != null) {
         sb.add(" ($osError)");
       }
     } else if (osError != null) {
       sb.add(": osError");
     }
     return sb.toString();
   }
   final String message;
   final OSError osError;
 }