Flushes any pending writes to the DOM by calling each ContextItem in the flushQueue.
function () {
        var me = this,
            items = me.flushQueue.clear(),
            length = items.length, i;

        if (length) {
            ++me.flushCount;

            for (i = 0; i < length; ++i) {
                items[i].flush();
            }
        }
    }