title: Custom MediaElement
body: <p>I am currently using some <code>MediaElements</code> in an application I am creating. I am dynamically creating them and adding them to a wrap panel. </p>
  
  <p>The problem is I need to be able to add a key to them so I can go back and locate a specific one. </p>
  
  <p>I was going to inherit from the <code>MediaElement</code> and just add the key as a member. Unfortunately I can't do this because it's a sealed class. </p>
  
  <p>So I tried to create a class containing a <code>MediaElement</code> and the key but I can't add that to the GUI since its not a <code>UIElement</code>.</p>
  
  <p>Is there anyway I can do this? I just need to be able to add <code>MediaElements</code> and them be able to go back and find them later so I can modify or remove them.</p>