Ok maybe I have something.

Gofer it
smalltalkhubUser: 'MathieuDehouck' project: 'RoassalAlgorithm';
package: 'RoassalAlgorithm';
load. 

Then try :

"Source code: ROMondrianExample>>treeLayoutOn:"
"Preambule. It includes the initialization. "
| view rawView |
rawView := ROView new.
view := ROMondrianViewBuilder view: rawView.
"-------------"
"-------------"

    
    view shape rectangle size: 45 ; color: Color green.
    view nodes: Magnitude withAllSubclasses.
    view edgesFrom: #superclass.
    
    view shape rectangle size: 20; color: Color blue.
    view nodes: ( Magnitude withAllSubclasses flatCollect: [ :e | e methodDict values ] ) .
    "view edgesFrom: [ :e | [e superclass] on: Exception do: [ e methodClass ]  ]."
    view layout: (ROMixingLayout withInner: (RORectanglePackingLayout new padding: 5) outer: RORadialTreeLayout  groupBy: [ :e | e methodClass ] ).
    
    "view edges do: [ :e | e - ROLine ]."

"-------------"
"-------------"
"Below is the initiation of the menu and opening the visualization"
ROEaselMorphic new populateMenuOn: view.
view open

Must bring you something like that the picture.

Regards

Mathieu