title: GWT - Vertical border line divides panel on two parts
body: <p>Does anyone know how to make, in GWT, panel which has a vertical boundary line that divides the panel on two parts same like this <a href="http://code.google.com/webtoolkit/overview.html" rel="nofollow noreferrer">http://code.google.com/webtoolkit/overview.html</a> ?</p>
  
  <p>I want when click on the blue border line to hide/show left menu same as on the above link.</p>
  
  <p>I can't to find any example of that.</p>
  
  <p>Thank you. </p>