title: How to restrict visibility of items?
body: <p>Imagine that we have an <code>AnchorPane</code>, it has child <code>Pane</code> and there we have <code>Button</code>, for example.<br>
  I want this <code>Button</code> to be shown only inside this <code>Pane</code>.<br>
  In other words, it whould be cut by the <code>Pane</code> edges if it is not completely within <code>Pane</code>. Now the <code>Button</code> can be visible even if it is out of <code>Pane</code> rectangle.</p>