nt.createElement('x-distribute');
    document.body.appendChild(d);
    var child = document.createElement('div');
    child.classList.add('child');
    child.textContent = 'Child';
    d.appendChild(child);
    flush();
    assert.equal(d.children[0], child, 'child not added to logical dom');
    testNoAttr();
    // set / unset `test` attr and see if it distributes properly
    child.setAttribute('slot', 'test');
    flush();
    testWithAttr();
    //
    child.removeAttribute('slot');
    flush();
    t