var expected = innerHTML + 'text';
        assert_equals(parent.innerHTML, expected);
    }, nodeName + '.after() with only text as an argument.');

    test(function() {
        var parent = document.createElement('div');
        var x = document.createElement('x');
        parent.appendChild(child);
        child.after(x);
        var expected = innerHTML + '<x></x>';
        assert_equals(parent.innerHTML, expected);
    }, nodeName + '.after() with only one element as an argument.');

    test(function(