title: Can't see value of request headers in firebase?
body: <p>I do the following:</p>
  
  <pre><code>var headers = new Headers();
  headers.append("bunny", "test");
  headers.append("rabbit", "jump");
  fetch("blahurl.com/someservice", {headers:headers})
  </code></pre>
  
  <p>On the firebase end:</p>
  
  <pre><code>export const listener = functions.https.onRequest(async (req, res) =&gt; {
   for (let entry of req.rawHeaders) {
          console.log(entry); // here I see a 'bunny,rabbit' get printed somewhere
      }
  
       //However this yields undefined:
       req.headers.bunny
  </code></pre>
  
  <p>Not sure how to get the header values, I just have the headers...</p>