title: unit testing for ArgumentNullException by param name
body: <p>I have a unit test and am checking for null exceptions of my controller constructor for a few different services.</p>
  
  <pre><code>[TestMethod]
  [ExpectedException(typeof(ArgumentNullException))]
  </code></pre>
  
  <p>In my controller constructor I have:</p>
  
  <pre><code> if (routeCategoryServices == null)
      throw new ArgumentNullException("routeCategoryServices");
  
   if (routeProfileDataService == null)
      throw new ArgumentNullException("routeProfileDataService");
  </code></pre>
  
  <p>I have a unit test for each, but how can I distinguish between the two. I can leave the test as is as either of the checks could be throwing null so I want to test the exception by param name. </p>
  
  <p>Is this possible?</p>