What is the lifespan of continuation tokens in DocumentDb : <p>I can't find anywhere in the documentation that indicates how long request continuation tokens last for DocumentDb paging support. I therefore suspect it is intentionally undefined.</p>

<p>In the real world, how long can I expect a token to last for? I ask this so that my app can present an error to the user when they are browsing through results that they have been started again, because the continuation token isn't valid.</p>
