using cssClassNames options for a table does not work

[sleekmountaincat]

hello,

class names get applied to the element in question, but the css for that class is not applied. with the following, i would expect to see a border around the header TR.

`

    <div class="chart-container">
        <google-chart type='table' options='{ "allowHtml": "true", "cssClassNames": {"headerRow": "mac"} }' data="[[ chartdata ]]"></google-chart>
    </div>

</template>`