title: css border style for treeview using bootstrap list-group-item
body: <p>I have a <code>treeview</code> using <code>bootstrap</code> style. which I wrote it myself..but I have problems with the style..I used <code>list-group</code> class for <code>ul</code> element and <code>list-group-item</code> for <code>li</code> element but my tree looks like below..how can I solve the border problem for child node and the whole with ?? </p>
  
  <p><a href="https://i.stack.imgur.com/zmwZV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zmwZV.png" alt="enter image description here"></a></p>
  
  <p>which should be like this</p>
  
  <p><a href="https://i.stack.imgur.com/lygxj.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lygxj.jpg" alt="enter image description here"></a></p>