anchor.diff:         * have no sense to have a toolboxUrl.
          */
         configureCustomToolboxFromUrl(toolboxUrl) {
  -        if (!this.readOnly) {
  -          $.get(toolboxUrl, (toolboxXml) => {
  -            this._initializeCustomToolboxBlocklyWorkspace(toolboxXml);
  -          });
  -        }
  +        if (this.readOnly) return;
  +
  +        console.debug('Configuring custom toolbox');
  +
  +        $.get(toolboxUrl, (toolboxXml) => {
  +          this._initializeCustomToolboxBlocklyWorkspace(toolboxXml);
  +        });
         },
   
         /**
  
positive.code:       },
  
        _setEditorToolbox: function () {
          const editor = $("mu-gobstones-custom-editor")[0];
  
          // editor may have not yet been loaded
          // so there is nothing to do yet
          if (!editor) return;
  
          editor.configureCustomToolboxFromUrl(this.toolboxUrl);
        }
      });
    </script>
  
negative.code:       },
  
        _initializeBlocklyWorkspace() {
          console.debug('Initializing Blockly Workspace');
  
          this._setInitialXml();
          this._initializeWorkspace();
          this._subscribeToWorkspace(() => this._updateSolution());
  