title: Akka-http: How to get User-Agent header from request header?
body: <p>I was trying to extract <code>User-agent</code> header from <code>Request-Header</code>, I tried this :</p>
  
  <pre><code> headerValue(extractUserAgent) { userAgent =&gt;
  
  }
  
  
  def extractUserAgent: HttpHeader =&gt; Option[String] = {
      case h: `User-Agent` =&gt; Some(h.)
      case x         =&gt; None
   }
  </code></pre>
  
  <p>I am stuck at line <code>Some(h.)</code>,I was thinking it might give some String values as <code>User-Agent</code> there, but not string values are inside of It.Help please!!</p>