code: public void updateNewModuleSelector() {
  
          ComboBox newModuleSelector = createModuleSelector();
          ((AbstractLayout)(m_moduleSelector.getParent())).replaceComponent(m_moduleSelector, newModuleSelector);
          m_moduleSelector = newModuleSelector;
          m_moduleSelector.addValueChangeListener(new ValueChangeListener() {
  
              private static final long serialVersionUID = 1L;
  
              public void valueChange(ValueChangeEvent event) {
  
                  String moduleName = (String)(event.getProperty().getValue());
                  addSelectableModule(moduleName);
                  updateNewModuleSelector();
              }
          });
      }
docs: Updates the selection widget for adding new modules.<p>