title: Given a TabPage, find its TabControl
body: <p>I have an instance of a <code>TabPage</code>.</p>
  
  <p>I want to ask that <code>TabPage</code>:</p>
  
  <blockquote>
    <p>"Who's your TabControl?"</p>
  </blockquote>
  
  <p>That is, I wish to query a <code>TabPage</code> to get a reference to the <code>TabControl</code> that contains it.</p>