title: how to replace an primeNg tree icon for a branch node to + or -?
body: <p>angular CLI version 6</p>
  
  <pre><code>"primeicons": "^1.0.0-beta.9",
  "primeng": "6.0.1",
  "font-awesome": "^4.7.0",
  </code></pre>
  
  <p>I am trying to change the default icon for tree node to + and -.
  I see suggested solutions here but I think they must for older version of the library since it does not work.</p>
  
  <p>Any guidance on this?</p>
  
  <p><a href="https://i.stack.imgur.com/bbbaz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bbbaz.png" alt="enter image description here"></a></p>