title: Multiple Invideo promotion using YouTube api
body: <p>I have to update multiple invideo promotion details for a particular channel.
  My request is as follows:</p>
  
  <pre><code>var requestOptions={
  part: 'invideoPromotion',   
  onBehalfOfContentOwner: 'contentOwner',         
  resource:{          
    id: channelId,
  
    invideoPromotion: {
  
      "defaultTiming": {
        "offsetMs": 2000,
        "type": "offsetFromStart"
      },
  
      "items": [
        {
          "promotedByContentOwner": true,
          "timing":
          {
              "offsetMs":4000,
              "duration" : 5000,
              "type":"offsetFromStart"
          },
          "id":{
              "videoId": videoid1,
              "type": "video"
          }
        },
        {
          "promotedByContentOwner": true,
          "timing":
          {
              "offsetMs":11000,
              "duration" : 5000,
              "type":"offsetFromStart"
          },
          "id":{
              "videoId": videoId2,
              "type": "video"
          }
        }
      ],
      "position": {
        "type": "corner",
        "cornerPosition": "topLeft"
      }
    }
  }
  };
  console.log(requestOptions);
  var request = gapi.client.youtube.channels.update(requestOptions);
  request.execute(function (response) {});
  </code></pre>
  
  <p>But when i try to execute this, I am getting error</p>
  
  <pre><code>0: {error:{code:500}, id:gapiRpc}
  error: {code:500}
  code: 500
  id: "gapiRpc"
  </code></pre>
  
  <p>Even When I try to do this using the youtube api explorer 
  <a href="https://developers.google.com/apis-explorer/#p/youtube/v3/youtube.channels.update" rel="nofollow">https://developers.google.com/apis-explorer/#p/youtube/v3/youtube.channels.update</a> ,
  I am getting Internal server Error.
  Can somebody let me know where I am going wrong.</p>