title: Error on class having definiton errors
body: <pre><code>InitializeComponent();
  
  var connectionString = "mongodb://localhost:27017";
  var client = new MongoClient(connectionString);
  var database = client.GetDatabase("test");
  var collection = database.GetCollection&lt;Rootobject&gt;("container");
  var res = collection.Aggregate().Group(x =&gt; x._event.NodeId,  x =&gt; new { Name = x.Key, WTs = x.Select(r =&gt; r._event.WT).ToList() }).ToList();
  
  cartesianChart1.Series = new SeriesCollection
  {
      new LineSeries
      {
          Title = res["event"]["NodeId"] ,
          Values = new ChartValues&lt;double&gt; {4.0, 3.9, 3.9, 3.85, 3.8, 3.8, 3.75}
      },
  }
  </code></pre>
  
  <p>The code above , i am trying to use my mongodb for my graphs input . But first i need to be able to query from MongoDB , i have come up with a var record but the 'NodeId' still has errors. it has <code>Event[] does not contain a definition for 'NodeID' and no extension method 'NodeId' accepting a first argument of type Event[]</code>. Below are my public classes</p>
  
  <pre><code>public class Rootobject
  {
      public string _id { get; set; }
      public Header[] header { get; set; }
      public Event[] _event { get; set; }
  }
  </code></pre>