title: ASP.NET can't cache null value
body: <p>Can anyone explain why you cannot insert a null object into the ASP.NET cache?</p>
  
  <pre><code>string exampleItem = null;
  
  HttpRuntime.Cache.Insert("EXAMPLE_KEY", 
                          exampleItem, 
                          Nothing,                           
                          DateTime.Now.AddHours(1),
                          System.Web.Caching.Cache.NoSlidingExpiration);
  </code></pre>
  
  <p>The exception error message states that the "value" object cannot be null. In my application there are valid reasons why we whould want to store a null value in the cache.</p>