nnerHTML, expected);
    }, nodeName + '.before() with some siblings of child as arguments; no changes in tree; viable sibling is first child.');

    test(function() {
        var parent = document.createElement('div')
        var v = document.createElement('v');
        var x = document.createElement('x');
        var y = document.createElement('y');
        var z = document.createElement('z');
        parent.appendChild(child);
        parent.appendChild(v);
        parent.appendChild(x);
        parent.