Started refactoring
diff --git a/gui/ngXosViews/serviceTopology/src/js/d3.js b/gui/ngXosViews/serviceTopology/src/js/d3.js
index d87ecda..52127a4 100644
--- a/gui/ngXosViews/serviceTopology/src/js/d3.js
+++ b/gui/ngXosViews/serviceTopology/src/js/d3.js
@@ -5,5 +5,10 @@
     .factory('d3', function($window){
       return $window.d3;
     })
+  .service('TreeLayout', function(){
+    this.updateTree = (source) => {
+
+    }
+  });
 
 }());
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