public class GeneralizationTypeAction implements IObjectActionDelegate {

    private Shell shell;
    private ArrayList<GeneralizationEditPart> selectedElements;
	
    /**
     * Constructor for Action.
     */
    public GeneralizationTypeAction() {
        super();
    }

    /**
     * @see IObjectActionDelegate#setActivePart(IAction, IWorkbenchPart)
     */
    public void setActivePart(IAction action, IWorkbenchPart targetPart) {
         shell = targetPart.getSite().getShell();
    }

    /**
     * @see IActionDelegate#run(IAction)
     */
    public void run(IAction action) {
        String menu = action.getId();
		
        if(menu.equals("UML_ER_tool.GroupGeneralization")){
            // Check if one of the Generalizations is already part of a Group
            ...
            // Create Generalization Category
            ...
				
            for (GeneralizationEditPart element : selectedElements) {
                GeneralizationImpl gen = (GeneralizationImpl)((View)element.getModel()).getElement();
					
                // Set Generalization Category in selected Generalizations
                ...
                // Set Tree Routing for selected GeneralizationImpl (= ConnectorImpl)
                ???
				
            }
            ...
        }
    ...