<svg xmlns="http://www.w3.org/2000/svg">
    <desc>Test that the instance of the 'class' attribute is animated and its renderer is invalidated correctly.</desc>
    <style>
        .red-fill {
            fill: red;
        }
        .green-fill {
            fill: green;
        }
    </style>
    <def>
        <rect id="rect" width="100" height="100" class="red-fill">
            <set id="green" attributeName="class" to="green-fill" fill="freeze"/>
        </rect>
    </def>
    <use href="#rect"/>
</svg>