title: xtext, modify outline tree string
body: <p>this is my <code>xtext</code> outline:</p>
  
  <p><a href="https://i.stack.imgur.com/XcbtK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XcbtK.png" alt="enter image description here"></a></p>
  
  <p>I would like to name by my self the unnamed fields.</p>
  
  <p>this is my outline tree provider code, it's not a final version : </p>
  
  <pre><code>class MyDslOutlineTreeProvider extends DefaultOutlineTreeProvider {
  
    def _createChildren(DocumentRootNode parentNode, Script test) {
         test.includes.forEach[v| createNode(parentNode,v)] 
  
         //test.assignments.forEach[a | createNode(parentNode,a)]
         test.tests.forEach[t|createNode(parentNode,t)]
    }
    def _createNode(IOutlineNode parentNode, Include modelElement) {      
  
    }
    def _createNode(IOutlineNode parentNode, Test modelElement) {
        // print ("RUN")
    }
  }
  </code></pre>