docs: private void setUpComboBoxTemplate() {
  
          try {
              I_CmsResourceType templateType = OpenCms.getResourceManager().getResourceType(
                  CmsResourceTypeJsp.getContainerPageTemplateTypeName());
              m_templates = m_clonedCms.readResources("/system/", CmsResourceFilter.DEFAULT.addRequireType(templateType));
              for (CmsResource res : m_templates) {
                  m_simpleFieldTemplate.addItem(res.getRootPath());
              }
  
              if (!m_templates.isEmpty()) {
                  m_simpleFieldTemplate.setValue(m_templates.get(0).getRootPath());
              }
  
              m_simpleFieldTemplate.setNewItemsAllowed(true);
              m_simpleFieldTemplate.setNullSelectionAllowed(true);
  
          } catch (CmsException e) {
              // should not happen
          }
      }