docs: public boolean isDefaultUser(String userName) {
  
          if (CmsStringUtil.isEmptyOrWhitespaceOnly(userName)) {
              return false;
          }
  
          // first check without ou prefix, to stay backwards compatible
          boolean isDefault = m_userAdmin.equals(userName);
          isDefault = isDefault || m_userGuest.equals(userName);
          isDefault = isDefault || m_userExport.equals(userName);
          isDefault = isDefault || m_userDeletedResource.equals(userName);
  
          // now check with ou prefix
          isDefault = isDefault || userName.equals(CmsOrganizationalUnit.SEPARATOR + m_userAdmin);
          isDefault = isDefault || userName.equals(CmsOrganizationalUnit.SEPARATOR + m_userGuest);
          isDefault = isDefault || userName.equals(CmsOrganizationalUnit.SEPARATOR + m_userExport);
          isDefault = isDefault || userName.equals(CmsOrganizationalUnit.SEPARATOR + m_userDeletedResource);
  
          return isDefault;
      }