title: Overwrite / update browser cookie
body: <p>I have an Express 4.x app, and I pass a cookie to the browser with</p>
  
  <pre><code>res.cookie('foo','bar1', {maxAge:99999999999});
  </code></pre>
  
  <p>it expires in the distant future. However, 5 minutes later, I get another request from the same user, and I want to give them a new cookie.</p>
  
  <pre><code> res.cookie('foo','bar2', {maxAge:99999999999});
  </code></pre>
  
  <p>From my debugging, it looks like the new cookie doesn't overwrite the old cookie? Is that the case? <strong>How can I update/overwrite the old cookie with the new one?</strong></p>