docs: private FlowPanel createTab() {
  
          FlowPanel tabPanel;
          tabPanel = new FlowPanel();
          tabPanel.addStyleName(ENTITY_CLASS);
          tabPanel.addStyleName(I_CmsLayoutBundle.INSTANCE.form().formParent());
          tabPanel.getElement().getStyle().setMargin(0, Unit.PX);
          return tabPanel;
      }