docs: protected void addConfiguration(
          CmsXmlContentDefinition contentDefinition,
          String elementName,
          String configurationValue)
      throws CmsXmlException {
  
          if (!elementName.contains("/") && (contentDefinition.getSchemaType(elementName) == null)) {
              throw new CmsXmlException(
                  Messages.get().container(Messages.ERR_XMLCONTENT_CONFIG_ELEM_UNKNOWN_1, elementName));
          }
  
          m_configurationValues.put(elementName, configurationValue);
      }