title: jQuery UI dialog - check if exists by instance method
body: <p>I'd like to use <code>instance</code> method for testing if jQuery UI Dialog widget has been initialized or not. Regarding to <a href="http://api.jqueryui.com/dialog/#method-instance">API</a>, this is possible, but it doesn't work for me:</p>
  
  <p><code>Uncaught Error: cannot call methods on dialog prior to initialization; attempted to call method 'instance'</code></p>
  
  <p>demo: <a href="http://jsfiddle.net/mDbV7/">http://jsfiddle.net/mDbV7/</a></p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>This was a mistake in the documentation, <code>instance</code> method will be available from version 1.11.0, see <a href="https://github.com/jquery/api.jqueryui.com/issues/117">this issue</a>.</p>