title: Add methods to base class c#
body: <p>Is that possible to add methods to Base classes like List? or others?
  I really need to add method to generic list class if it has MyClass type.
  like this:
  <code>List&lt;MyClass&gt;.FindCoolStuff()</code> or <code>List&lt;MyClass&gt;.SetValueByName()</code></p>
  
  <p>thanks</p>