title: Why no value is being set for nullable and optional parameter
body: <p>I am trying following code.</p>
  
  <pre><code>TestMethod(null, null);    
  
  public static void TestMethod(int? x = 10, int? y = 20)
          {
              var message = $"The value of x is {x.Value} and y is {y.Value}";
          }
  </code></pre>
  
  <p>I am not able to understand why the Value property of <code>x</code> is <code>null</code> despite I have set their default values in parameters?</p>
  
  <p><a href="https://i.stack.imgur.com/zqMCN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zqMCN.png" alt="Nullable &amp; Optional Parameter"></a></p>