docs: protected void createLoadingAnimation(String msg) {
  
          m_clientLoading = true;
          if (m_loadingPanel != null) {
              m_loadingPanel.removeFromParent();
          }
          m_loadingPanel = new FlowPanel();
          m_loadingPanel.addStyleName(
              org.opencms.gwt.client.ui.css.I_CmsLayoutBundle.INSTANCE.uploadButton().loadingPanel());
          m_loadingPanel.addStyleName(m_gwtCss.generalCss().cornerAll());
  
          CmsLoadingAnimation animationDiv = new CmsLoadingAnimation();
          animationDiv.addStyleName(
              org.opencms.gwt.client.ui.css.I_CmsLayoutBundle.INSTANCE.uploadButton().loadingAnimation());
          m_loadingPanel.add(animationDiv);
  
          HTML messageDiv = new HTML();
          messageDiv.addStyleName(org.opencms.gwt.client.ui.css.I_CmsLayoutBundle.INSTANCE.uploadButton().loadingText());
          messageDiv.setHTML(msg);
          m_loadingPanel.add(messageDiv);
  
          m_contentWrapper.add(m_loadingPanel);
          doResize();
      }