title: WPF: Dictionary<int, List<string>> in DataGrid
body: <p>I have a <code>Dictionary&lt;int, List&lt;string&gt;&gt;</code>. Each ID(int) has a corresponding dynamic list of names(<code>List&lt;string&gt;</code>).</p>
  
  <p>This is the expected output in Datagrid.</p>
  
  <pre><code>ID | Name | Name | Name
  1    Ash    Tina   Kara
  2    Kc     
  3    Star   Lara
  </code></pre>
  
  <p>How do I achieve this?</p>