title: Set HTTP GET Parameters in Finagle
body: <p>In Finagle, how do I create a request an HTTP GET request with parameters in a safe, clean way?</p>
  
  <pre><code>val request = RequestBuilder()
    .url("http://www.example.com/test")
    .addParameter("key", "value")   // this doesn't exist
    .buildGet()
  request    // should be a GET request for http://www.example.com/test?key=value
  </code></pre>