title: How to handle a class you want to extend which is sealed in the .NET library?
body: <p>I was reading somewhere about how to handle the issue of wanting to extend a sealed class in the .NET Framework library.</p>
  
  <p>This is often a common and useful task to do, so it got me thinking, in this case, what solutions are there? I believe there was a "method" demonstrated to extend a sealed class in the article I read, but I cannot remember now (it wasn't extension methods).</p>
  
  <p>Is there any other way?
  Thanks</p>