@Override
 public void removeModelElement(Object modelElement) throws ReadOnlyElementException {
   SessionManager.getInstance().createSession(IGUILabels.TITLE + ": remove package");
   ModelElementsManager.getInstance().removeElement((Element) modelElement);
   SessionManager.getInstance().closeSession();
 }
  public void addDiagramTable(Tree tree, NamedElement father, Element after) {
    ElementsFactory factory = null;

    if (!SessionManager.getInstance().isSessionCreated()) {

      SessionManager.getInstance().createSession("MBSE-doc");
      factory = Application.getInstance().getProject().getElementsFactory();

      ArrayList<Class<?>> select = new ArrayList<Class<?>>();
      select.add(com.nomagic.uml2.ext.magicdraw.classes.mdkernel.Diagram.class);

      ArrayList<Class<?>> display = new ArrayList<Class<?>>();
      display.add(com.nomagic.uml2.ext.magicdraw.classes.mdkernel.Package.class);
      display.add(com.nomagic.uml2.ext.magicdraw.classes.mdkernel.Class.class);
      display.add(com.nomagic.uml2.ext.magicdraw.mdprofiles.Profile.class);

      ArrayList<Class<?>> create = new ArrayList<Class<?>>();

      ArrayList<Class<?>> restricted = new ArrayList<Class<?>>();

      SelectElementTypes seTypes = new SelectElementTypes(display, select, create, restricted);

      // Martynas says: ElementSelectionDlg is preferred

      SelectElementInfo sei =
          new SelectElementInfo(
              true, true, Application.getInstance().getProject().getModel(), true);

      ElementSelectionDlg dlg =
          ElementSelectionDlgFactory.create(MDDialogParentProvider.getProvider().getDialogParent());
      ElementSelectionDlgFactory.initSingle(
          dlg, seTypes, sei, Application.getInstance().getProject().getModel());
      dlg.show();

      if (dlg.getResult() == com.nomagic.ui.DialogConstants.OK
          && dlg.getSelectedElement() != null) {
        BaseElement be = dlg.getSelectedElement();

        com.nomagic.uml2.ext.magicdraw.classes.mdkernel.Class theTable =
            factory.createClassInstance();
        StereotypesHelper.addStereotype(theTable, ut.getTheTableDiagramStereotype());

        try {
          ModelElementsManager.getInstance().addElement(theTable, father);

        } catch (ReadOnlyElementException roee) {
          Utilities.displayWarning("Read only element");
        }

        // add hyperlink to selected model element
        final Stereotype hyperlinkOwnerStereotype =
            StereotypesHelper.getStereotype(
                Application.getInstance().getProject(), "HyperlinkOwner");
        StereotypesHelper.addStereotype(theTable, hyperlinkOwnerStereotype);
        StereotypesHelper.setStereotypePropertyValue(
            theTable, hyperlinkOwnerStereotype, "hyperlinkModel", be, true);
        StereotypesHelper.setStereotypePropertyValue(
            theTable, hyperlinkOwnerStereotype, "hyperlinkModelActive", be, false);

        if (StereotypesHelper.hasStereotypeOrDerived(father, "section")) {
          StereotypesHelper.setStereotypePropertyValue(
              father, ut.getTheSectionStereotype(), "blockelements", theTable, true);
        } else if (StereotypesHelper.hasStereotypeOrDerived(father, "chapter")) {
          StereotypesHelper.setStereotypePropertyValue(
              father, ut.getTheChapterStereotype(), "blockelements", theTable, true);
        }

        // set tag to selected diagram
        StereotypesHelper.setStereotypePropertyValue(
            theTable, ut.getTheTableDiagramStereotype(), "diagramTable", be, true);
        // set tag with caption text
        StereotypesHelper.setStereotypePropertyValue(
            theTable, ut.getTheTableDiagramStereotype(), "captionText", be.getHumanName(), true);
        theTable.setName(be.getHumanName());
        tree.openNode(theTable, true, true);
        MBSEShowEditPanelAction.updateEditorView(father, theTable, "tableDiagram");

      } else {
        System.out.println("User cancelled Diagram selection");
      }

      SessionManager.getInstance().closeSession();
    } else {
      Utilities.displayWarning("could not create session manager");
    }
  }