'get selected', function(done) {
        asyncPlatformFlush(function() {
          // check selected class
          assert.isTrue(s.children[0].classList.contains('core-selected'));
          done();
        });
      });

      test('set selected', function(done) {
        // set selected
        s.selected = 'item1';
        asyncPlatformFlush(function() {
          // check selected class
          assert.isTrue(s.children[1].classList.contains('core-selected'));
          done();
        });
      });
