title: How to empty IEnumerable list?
body: <p>I need to empty <code>IEnumerable</code> list i tried many things like null and none of them worked</p>
  
  <p>this how my model looks like</p>
  
  <pre><code>public class NewsViewModel
  {
      public NewsViewModel()
      {
          this.Categories = new List&lt;Category&gt;();
      }
  
      public int NewsId { get; set; }
      public string NewsTitle { get; set; }
      public string NewsBody { get; set; }
  
      public IEnumerable&lt;Category&gt; Categories { get; set; }
  }
  
  if (!string.IsNullOrEmpty(SelectedCategoriesIds))
  {
      List&lt;Category&gt; stringList = new List&lt;Category&gt;();
      stringList.AddRange(SelectedCategoriesIds.Split(',').Select(i =&gt; new Category() { CategoryId = int.Parse(i) }));
      model.Categories = stringList.AsEnumerable();
  }
  else
  {
      model.Categories = null;
  }
  </code></pre>
  
  <p>How to make <code>model.Categories</code> empty ?</p>