code: public void openEditDialog(String siteRoot) {
  
          CmsEditSiteForm form;
          String caption;
          if (siteRoot != null) {
              form = new CmsEditSiteForm(m_rootCms, this, siteRoot);
              caption = CmsVaadinUtils.getMessageText(
                  Messages.GUI_SITE_CONFIGURATION_EDIT_1,
                  m_sitesTable.getContainer().getItem(siteRoot).getItemProperty(TableProperty.Title).getValue());
          } else {
              form = new CmsEditSiteForm(m_rootCms, this);
              caption = CmsVaadinUtils.getMessageText(Messages.GUI_SITE_ADD_0);
          }
          openDialog(form, caption);
      }
docs: Opens the edit site dialog.<p>
  
  @param siteRoot the site root of the site to edit, if <code>null</code>