title: Voximplant: switching language in DialogFlow
body: <p>I have a DialogFlow integration working in my Voximplant application.
  Now I add a language to dialogflow agent.
  I didnt't find a way to dynamically switch language in this telephony integration.</p>
  <p>Should I just send the user to select the language before integration start?
  What's is the best approach here?</p>