title: Archive a NSMutableArray
body: <p>I need to archive a NSMutableArray which is being controlled by an ArrayController. I tried this:</p>
  
  <pre><code>[NSKeyedArchiver archivedDataWithRootObject:array];
  </code></pre>
  
  <p>But I got this error:</p>
  
  <blockquote>
    <p><code>*** -[NSKeyedArchiver dealloc]: warning: NSKeyedArchiver deallocated
    without having had -finishEncoding
    called on it.</code></p>
  </blockquote>
  
  <p>How may I solve that please?</p>