title: Dialogflow - Google Assistant: setFollowupEvent after showing a message
body: <p>Here it is my use case: somewhere in my fulfillment, while handling the Intent A, I want to call Intent B using <code>setFollowupEvent</code>. Something like:</p>
  
  <pre><code>function intentA_Handler(){
      ....
      agent.add('This is the response when calling Intent A');
      agent.setFollowupEvent('call_intent_B_event');
  }
  
  function intentB_Handler(){
      agent.add('I am in intent B now.');
      ....
  }
  </code></pre>
  
  <p>What I'm expecting:</p>
  
  <ol>
  <li>The assistant Shows &amp; Speaks out the string <strong>This is the response when calling Intent A</strong></li>
  <li>Then calling <code>agent.setFollowupEvent('call_intent_B_event');</code> and Showing &amp; Speaking out the string <strong>I am in intent B now.</strong></li>
  </ol>
  
  <p>What happens:</p>
  
  <p>The assistant immediately shows &amp; speaks out to me the string <strong>I am in intent B now</strong> and omits the first string <strong>This is the response when calling Intent A</strong> </p>
  
  <p>Already tried:</p>
  
  <pre><code>function intentA_Handler(){
      ....
      new Promise((resolve, reject) =&gt; {
          agent.add('This is the response when calling Intent A');
          resolve();
      });
  
      agent.setFollowupEvent('call_intent_B_event');
  }
  </code></pre>
  
  <p>But still the same result. Any idea how to achieve my goal?</p>