diff --git a/cameleer3-server-app/src/test/java/com/cameleer3/server/app/diagram/ElkDiagramRendererTest.java b/cameleer3-server-app/src/test/java/com/cameleer3/server/app/diagram/ElkDiagramRendererTest.java
index 4b5fbeaf..84e994ab 100644
--- a/cameleer3-server-app/src/test/java/com/cameleer3/server/app/diagram/ElkDiagramRendererTest.java
+++ b/cameleer3-server-app/src/test/java/com/cameleer3/server/app/diagram/ElkDiagramRendererTest.java
@@ -39,7 +39,8 @@ class ElkDiagramRendererTest {
         RouteNode process = new RouteNode("node-2", NodeType.BEAN, "myProcessor");
         RouteNode to = new RouteNode("node-3", NodeType.TO, "log:output");
 
-        graph.setNodes(List.of(from, process, to));
+        from.setChildren(List.of(process, to));
+        graph.setRoot(from);
         graph.setEdges(List.of(
                 new RouteEdge("node-1", "node-2", RouteEdge.EdgeType.FLOW),
                 new RouteEdge("node-2", "node-3", RouteEdge.EdgeType.FLOW)
@@ -62,10 +63,10 @@ class ElkDiagramRendererTest {
         RouteNode otherwise = new RouteNode("node-4", NodeType.EIP_OTHERWISE, "otherwise");
         RouteNode to = new RouteNode("node-5", NodeType.TO, "log:result");
 
-        // Set children on the choice node
+        // Build tree: from → [choice, to]; choice → [when, otherwise]
         choice.setChildren(List.of(when, otherwise));
-
-        graph.setNodes(List.of(from, choice, when, otherwise, to));
+        from.setChildren(List.of(choice, to));
+        graph.setRoot(from);
         graph.setEdges(List.of(
                 new RouteEdge("node-1", "node-2", RouteEdge.EdgeType.FLOW),
                 new RouteEdge("node-2", "node-3", RouteEdge.EdgeType.FLOW),
@@ -193,9 +194,8 @@ class ElkDiagramRendererTest {
         doFinally.setChildren(List.of(cleanup));
         doCatch.setChildren(List.of(errorLog));
         doTry.setChildren(List.of(process, log1, doFinally, doCatch));
-
+        from.setChildren(List.of(doTry, to));
         graph.setRoot(from);
-        graph.setNodes(List.of(from, doTry, process, log1, doFinally, cleanup, doCatch, errorLog, to));
         graph.setEdges(List.of(
                 new RouteEdge("node-1", "node-2", RouteEdge.EdgeType.FLOW),
                 new RouteEdge("node-2", "node-3", RouteEdge.EdgeType.FLOW),