title: What does "this[0]" mean in C#?
body: <p>I was going through some library code and saw a method like:</p>
  
  <pre><code>public CollapsingRecordNodeItemList List
  {
      get { return this[0] as CollapsingRecordNodeItemList; }
  }
  </code></pre>
  
  <p>The class that contains this method is not a list or something iterable, so what exactly does <code>this[0]</code> mean?</p>