title: Custom payload in Dialogflow
body: <p>i try to send custom payload in Dialogflow from fulfillment(nodejs)</p>
  
  <p>My motive is send link and its text as response to web page.</p>
  
  <p>my sample code for reference:</p>
  
  <pre><code>  const response = {
        messages: [
          {
            payload: {
              messages: [
                {
                  speech: 'here are some quick links for your convenience.',
                  linkmessage: [{
                    message: 'google',
                    link: 'www.google.com'
                  }, {
                    message: 'yahoo',
                    link: 'www.yahoo.co.in'
                  }],
                  button: [{
                    buttonname: 'more page'
                  }]
                }
              ]
            }
          }
        ]
      };
      agent.add(new Payload(agent.UNSPECIFIED, response, { rawPayload: true, sendAsMessage: true}));
  </code></pre>
  
  <p>Here i get the response as:</p>
  
  <pre><code>{
      "fulfillment": {
        "speech": "",
        "messages": [
          {
            "lang": "en",
            "type": 0,
            "speech": ""
          }
        ],
        "data": {
          "null": {
            "messages": [
              {
                "payload": {
                  "messages": [
                    {
                      "speech": "here are some quick links for your convenience.",
                      "linkmessage": [{
                        "message": "google",
                        "link": "www.google.com"
                      }, {
                        "message": "yahoo",
                        "link": "www.yahoo.co.in"
                      }],
                      "button": [{
                        "buttonname": "more page"
                      }]
                    }
                  ]
                }
              }
            ]
          }
        }
      }
  </code></pre>
  
  <p>Here you can see in response i am getting "<strong>null</strong>" object is appended inside the data object in the response.</p>
  
  <p>can any one help me out to remove that <strong>null</strong> object from dialogflow response, and any other option for sending custom payload from fulfillment nodejs.</p>