title: If null.Equals(null) why do I get a NullReferenceException
body: <p>I have the following line of code:</p>
  
  <pre><code>var selectedDomainID = lkuDomainType.EditValue.Equals(null) 
      ? string.Empty 
      : lkuDomainType.EditValue;
  </code></pre>
  
  <p>Sometimes this generates a <code>NullReferenceException</code>. What I don't understand is why. Isn't the whole point of my code to check for <code>null</code> and if so assign <code>string.empty</code>?  When I check in DEBUG it is stating that <code>EditValue == null</code> so what am I missing?</p>