title: Cache == null? Is it possible?
body: <p>Is it legal to make the following statement:</p>
  
  <pre><code>if(Cache[CACHE_KEY] == null)
  {
      //do something to form cache
  }
  else
  {
      //do something else that uses cache
  }
  </code></pre>
  
  <p>I'm not sure my program is actually functioning properly (even though it compiles) and am wondering if a cache doesn't exist is it set to null?</p>