title: Property cannot be declared public because its type uses an internal type
body: <p>I created two classes <code>Content</code> and <code>Bucket</code>.  <code>Bucket</code> contains an array of <code>Content</code> objects and exposes that via a public property.  However, when I do so, I receive the error:</p>
  
  <blockquote>
    <p>Property cannot be declared public because its type uses an internal type</p>
  </blockquote>
  
  <p><a href="https://i.stack.imgur.com/LukDn.png" rel="noreferrer"><img src="https://i.stack.imgur.com/LukDn.png" alt="enter image description here"></a></p>
  
  <p>Any thoughts on why this is raising an error?</p>