code: public Button addSubNavEntry(final NavEntry navEntry) {
  
          Button button = CmsDefaultAppButtonProvider.createIconButton(
              navEntry.getName(),
              navEntry.getDescription(),
              navEntry.getIcon());
          m_subNav.addComponent(button);
          return button;
      }
docs: Adds a sub navigation entry.<p>
  
  @param navEntry the entry to add
  
  @return the entry button component