title: Adding JArray to an existing property
body: <p>I have this JSON:</p>
  
  <pre><code>{
    "ID":123,
    "Products":null,
    "Title":"Products"
  }
  </code></pre>
  
  <p>I want to add some data from DB to the "Products" node so my final json will look like so:</p>
  
  <pre><code>{
    "ID":123,
    "Products":[
        {
          "ID":1,
          "Name":"AA"
        },
        {
          "ID":2,
          "Name":"BB"
        }
      ],
    "Title":"Products"
  }
  </code></pre>
  
  <p>I'm using this code:</p>
  
  <pre><code>internal class Product
  {
      public int ID { get; set; }
      public string Name { get; set; }
  }
  
  //simulate DB
  var products= new List&lt;Product&gt;()
  {
      new Product() {ID=1,Name="AA" },
      new Product() {ID=2,Name="BB" }
  };
  
  string JSONstr = FilesUtils.OpenFile(Path.Combine(Environment.CurrentDirectory, "Sample.json"));
  JObject JSON = JObject.Parse(JSONstr);
          ((JValue)JSON["Products"]).Value = JObject.FromObject(products); 
  </code></pre>
  
  <p>But I get an exception: </p>
  
  <blockquote>
    <p>Object serialized to Array. JObject instance expected.</p>
  </blockquote>