title: TypeError: $(...).parents(...).size is not a function
body: <p>I have a basic script which allows me to click on the website's background, excluding <code>#content</code>.</p>
  
  <p>After upgrading jQuery to 3.1.0 version, I get this error:
  <code>TypeError: $(...).parents(...).size is not a function</code>.</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
    $(function() {
      $("#background").click(function(e) {
        if (e.target.id == "wrapper" || $(e.target).parents("#wrapper").size()) 
        {
          // do nothing
        } 
        else
        {
          window.open('http://example.com');
        }
      });
    })
  &lt;/script&gt;`
  </code></pre>
  
  <p>I don't know how to fix it. jQuery is loaded properly. Please help.</p>