 from attribute.
            var dialog = fixture('like-modal');
            assert.isTrue(dialog[property], property + ' is true');
          });

          test('modal toggling keeps previous value of ' + property + ' (attribute)', function() {
            // Property is set on ready from attribute.
            var dialog = fixture('like-modal');
            // Toggle twice to trigger observer.
            dialog.modal = true;
            dialog.modal = false;
            assert.isTrue(dialog[property], p