title: Fire an event when Collection Changed (add or remove)
body: <p>I have a class which contains a list :</p>
  <pre><code>public class a
  {
      private List&lt;MyType&gt; _Children;
  
      public Children
      {
          get { return(_Children); }
          set { _Children = value ; }
      }
  }
  </code></pre>
  <p>I want to create an event and fire it whenever my list (_Children here) is changed for example an item is added to it or removed from it or it's cleared.</p>
  <p>thanks</p>