title: Remove duplicate from JObject
body: <p>I have a JSON string like this:</p>
  
  <pre><code>{
      "managedObjects": [
           {
              "id": "13289",      
              "name": "xxx"      
           },
           {
              "id": "13290",      
              "name": "yyy" 
           },
           {
              "id": "13289",      
              "name": "xxx" 
           }]
  }
  </code></pre>
  
  <p>I'm parsing to JObject</p>
  
  <pre><code>JObject obj = JObject.Parse(json)
  </code></pre>
  
  <p>Now, how to remove the duplicate element from this array? I want to remove duplicate element by id from JObject (here <code>id=13289</code>).</p>