tion() {
          assert.isTrue(c1.getAttribute('aria-checked') == 'true');
          assert.isTrue(c1.checked);
          done();
        });
        MockInteractions.tap(c1);
      });

      test('toggle checkbox via click', function(done) {
        c1.checked = true;
        c1.addEventListener('click', function() {
          assert.isFalse(c1.getAttribute('aria-checked') != 'false');
          assert.isFalse(c1.checked);
          done();
        });
        MockInteractions.tap(c1);
      });

      