code: private void updateBundleDescriptorContent() throws CmsXmlException {
  
          if (m_descContent.hasLocale(Descriptor.LOCALE)) {
              m_descContent.removeLocale(Descriptor.LOCALE);
          }
          m_descContent.addLocale(m_cms, Descriptor.LOCALE);
  
          int i = 0;
          Property<Object> descProp;
          String desc;
          Property<Object> defaultValueProp;
          String defaultValue;
          Map<String, Item> keyItemMap = getKeyItemMap();
          List<String> keys = new ArrayList<String>(keyItemMap.keySet());
          Collections.sort(keys, CmsCaseInsensitiveStringComparator.getInstance());
          for (Object key : keys) {
              if ((null != key) && !key.toString().isEmpty()) {
  
                  m_descContent.addValue(m_cms, Descriptor.N_MESSAGE, Descriptor.LOCALE, i);
                  i++;
                  String messagePrefix = Descriptor.N_MESSAGE + "[" + i + "]/";
  
                  m_descContent.getValue(messagePrefix + Descriptor.N_KEY, Descriptor.LOCALE).setStringValue(
                      m_cms,
                      (String)key);
                  descProp = keyItemMap.get(key).getItemProperty(TableProperty.DESCRIPTION);
                  if ((null != descProp) && (null != descProp.getValue())) {
                      desc = descProp.getValue().toString();
                      m_descContent.getValue(messagePrefix + Descriptor.N_DESCRIPTION, Descriptor.LOCALE).setStringValue(
                          m_cms,
                          desc);
                  }
  
                  defaultValueProp = keyItemMap.get(key).getItemProperty(TableProperty.DEFAULT);
                  if ((null != defaultValueProp) && (null != defaultValueProp.getValue())) {
                      defaultValue = defaultValueProp.getValue().toString();
                      m_descContent.getValue(messagePrefix + Descriptor.N_DEFAULT, Descriptor.LOCALE).setStringValue(
                          m_cms,
                          defaultValue);
                  }
  
              }
          }
  
      }
docs: Update the descriptor content with values from the editor.
  @throws CmsXmlException thrown if update fails due to a wrong XML structure (should never happen)