title: typeError: Failed to execute 'contains' on 'Node': parameter 1 is not of type 'Node Polymer
body: <p>I am trying to implement context menu using polymer paper menu. Whenever I remove node from dom. <code>polymer</code> is throwing error like this  </p>
  
  <blockquote>
    <p>typeError: Failed to execute 'contains' on 'Node': parameter 1 is not of type 'Node'</p>
  </blockquote>
  
  <p>and I get the following error message:</p>
  
  <p><a href="https://i.stack.imgur.com/KioEL.png" rel="noreferrer"><img src="https://i.stack.imgur.com/KioEL.png" alt="Error screenshot attached"></a></p>
  
  <p>What shall I do?</p>