title: Can you add to an enum type in run-time
body: <p>If I have an enum type:</p>
  
  <pre><code>public enum Sport
  {
      Tennis = 0;
      Football = 1;
      Squash = 2;
      Volleyball = 3;
  }
  </code></pre>
  
  <p>Can I somehow add during run-time:</p>
  
  <pre><code>PingPong = 4
  </code></pre>