function setup(ownedIds, ownerIds, attributeValue) {
        var fixture = document.getElementById('qunit-fixture');
        var value = attributeValue || ownedIds.join(' ');
        ownedIds.forEach(function(id) {
            var element = document.createElement('div');
            element.id = id;
            fixture.appendChild(element);
        });
        ownerIds = ownerIds || [''];
        ownerIds.forEach(function(id) {
            var element = document.createElement('div');
            if (id) {  // could be an empty string, that is legit here
                element.id = id;
            }
            element.setAttribute('aria-owns', value);
            fixture.appendChild(element);
        });
        return fixture;
    }
Helper for aria-owns testing:
 - adds owned elements to the fixture
 - creates owner element/s
 - sets aria-owns on owners
 - returns the fixture
@param {!Array.<string>} ownedIds The ids that will be 'owned'.
@param {Array.<string>} ownerIds An id for each 'owner' element.
@param {string=} attributeValue The value of 'aria-owns'
   otherwise the ownedIds will be used.
@return {!Element} The test container (qunit fixture).