Make isEmpty a getter.

tests/html/documentfragment_test.dart

 // Copyright (c) 2011, 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('DocumentFragmentTest');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 #source('util.dart');
 
@@ skipping 99 matching lines @@
       elements = fragment.elements;
       fragment.nodes.addAll(
         [new Text("1"), new Element.tag("A"), new Element.tag("B"),
          new Text("2"), new Element.tag("I"), new Text("3"),
          new Element.tag("U")]);
     };
 
     test('is initially empty', () {
       elements = new DocumentFragment().elements;
       Expect.listEquals([], elements);
-      Expect.isTrue(elements.isEmpty());
+      Expect.isTrue(elements.isEmpty);
     });
 
     test('filters out non-element nodes', () {
       init();
       Expect.listEquals(["1", "A", "B", "2", "I", "3", "U"],
                         _nodeStrings(fragment.nodes));
       Expect.listEquals(["A", "B", "I", "U"], _nodeStrings(elements));
     });
 
     test('only indexes elements, not other nodes', () {
@@ skipping 25 matching lines @@
       Expect.listEquals(["A", "B"], _nodeStrings(elements));
     });
 
     test('accessors are wrapped', () {
       init();
       Expect.equals("A", elements[0].tagName);
       Expect.listEquals(
           ["I"], _nodeStrings(elements.filter((e) => e.tagName == "I")));
       Expect.isTrue(elements.every((e) => e is Element));
       Expect.isTrue(elements.some((e) => e.tagName == "U"));
-      Expect.isFalse(elements.isEmpty());
+      Expect.isFalse(elements.isEmpty);
       Expect.equals(4, elements.length);
       Expect.equals("I", elements[2].tagName);
       Expect.equals("U", elements.last().tagName);
     });
 
     test('setting elements overwrites nodes as well', () {
       init();
       fragment.elements = [new Element.tag("DIV"), new Element.tag("HEAD")];
       Expect.listEquals(["DIV", "HEAD"], _nodeStrings(fragment.nodes));
     });
@@ skipping 114 matching lines @@
     fragment.webkitRequestFullScreen(2);
   });
 
   test('default values', () {
     var fragment = new DocumentFragment();
     fragment.rect.then(expectAsync1((ElementRect rect) {
        expectEmptyRect(rect.client);
        expectEmptyRect(rect.offset);
        expectEmptyRect(rect.scroll);
        expectEmptyRect(rect.bounding);
-       Expect.isTrue(rect.clientRects.isEmpty());
+       Expect.isTrue(rect.clientRects.isEmpty);
     }));
     Expect.equals("false", fragment.contentEditable);
     Expect.equals(-1, fragment.tabIndex);
     Expect.equals("", fragment.id);
     Expect.equals("", fragment.title);
     Expect.equals("", fragment.tagName);
     Expect.equals("", fragment.webkitdropzone);
     Expect.equals("", fragment.webkitRegionOverflow);
     Expect.isFalse(fragment.isContentEditable);
     Expect.isFalse(fragment.draggable);
     Expect.isFalse(fragment.hidden);
     Expect.isFalse(fragment.spellcheck);
     Expect.isFalse(fragment.translate);
     Expect.isNull(fragment.nextElementSibling);
     Expect.isNull(fragment.previousElementSibling);
     Expect.isNull(fragment.offsetParent);
     Expect.isNull(fragment.parent);
-    Expect.isTrue(fragment.attributes.isEmpty());
-    Expect.isTrue(fragment.classes.isEmpty());
-    Expect.isTrue(fragment.dataAttributes.isEmpty());
+    Expect.isTrue(fragment.attributes.isEmpty);
+    Expect.isTrue(fragment.classes.isEmpty);
+    Expect.isTrue(fragment.dataAttributes.isEmpty);
     Expect.isFalse(fragment.matchesSelector("foo"));
     Expect.isFalse(fragment.matchesSelector("*"));
   });
 
   test('style', () {
     var fragment = new DocumentFragment();
     var style = fragment.style;
     expectEmptyStyleDeclaration(style);
     fragment.computedStyle.then(expectAsync1((computedStyle) {
       expectEmptyStyleDeclaration(computedStyle);
@@ skipping 13 matching lines @@
   //   // assertConstError(() => fragment.classes.add('foo'));
   // });
 
   test('query searches the fragment', () {
     var fragment = new DocumentFragment.html(
       "<div class='foo'><a>foo</a><b>bar</b></div>");
     Expect.equals("A", fragment.query(".foo a").tagName);
     Expect.listEquals(["A", "B"], _nodeStrings(fragment.queryAll(".foo *")));
   });
 }