title: GetHashCode() behaviour work when Dictionary has more than Int.MaxValue elements
body: <p><code>GetHashCode()</code> returns a <code>int32</code> as hash. </p>
  
  <p>I was wondering how would it work when the number of elements exceed <code>int.MaxValue</code>, as all of them would have returned some integer <code>&lt;= int.MaxValue</code>?</p>