title: Go net/http handle func with dynamic uri segment
body: <p>How i can use dynamic uri segment in Go net/http ? for example</p>
  
  <pre><code>http.HandleFunc("/&lt;user_id&gt;/&lt;file_id&gt;", HelloServer)
  </code></pre>
  
  <p>it is possible to do this with only Go built-in net/http ?</p>