How do I get the default scene GUI for a CustomEditor for RectTransform?

I am trying to extend the default RectTransform to add some buttons with simple functionalities.
I know how to draw the default inspector to extend the RectTransform like this:
Editor defaultEditor;

void OnEnable(){
    defaultEditor = Editor.CreateEditor(targets, Type.GetType("UnityEditor.RectTransformEditor, UnityEditor"));

public override void OnInspectorGUI()

But I am not able to draw the default gizmos in the scene view, i.e. the anchors, which should also be intractable:

(the picture on the left is with the extension, the two pictures on the right are without).

is there a way to draw the default scene gizmos (I am assuming they are gizmos) in the same ways we are drawing the default inspector?

Finally found the answer here:

private void OnSceneGUI() {
    MethodInfo onSceneGUI_Method = defaultEditor.GetType().GetMethod("OnSceneGUI", BindingFlags.NonPublic | BindingFlags.Instance);
    onSceneGUI_Method.Invoke(defaultEditor, null);