JSR 286 Exercise 2 Solution

    ...
    <portlet>
        ...
        <supported-public-render-parameter>preferredState</supported-public-render-parameter>
    </portlet>
    ...
    <public-render-parameter>
        <identifier>preferredState</identifier>
        <name>preferredState</name>
    </public-render-parameter>

</portlet-app>