docs: private void initMetaMappings() {
  
          if (m_metaMappings == null) {
              m_metaMappings = new HashMap<String, MetaMapping>();
              try {
                  initPage();
                  CmsMacroResolver resolver = new CmsMacroResolver();
                  resolver.setKeepEmptyMacros(true);
                  resolver.setCmsObject(m_cms);
                  resolver.setMessages(OpenCms.getWorkplaceManager().getMessages(getLocale()));
                  CmsResourceFilter filter = getIsEditMode()
                  ? CmsResourceFilter.IGNORE_EXPIRATION
                  : CmsResourceFilter.DEFAULT;
                  for (CmsContainerBean container : m_page.getContainers().values()) {
                      for (CmsContainerElementBean element : container.getElements()) {
                          String settingsKey = CmsFormatterConfig.getSettingsKeyForContainer(container.getName());
                          String formatterConfigId = element.getSettings() != null
                          ? element.getSettings().get(settingsKey)
                          : null;
                          I_CmsFormatterBean formatterBean = null;
                          if (CmsUUID.isValidUUID(formatterConfigId)) {
                              formatterBean = OpenCms.getADEManager().getCachedFormatters(
                                  m_cms.getRequestContext().getCurrentProject().isOnlineProject()).getFormatters().get(
                                      new CmsUUID(formatterConfigId));
                          }
                          if ((formatterBean != null)
                              && formatterBean.useMetaMappingsForNormalElements()
                              && m_cms.existsResource(element.getId(), filter)) {
                              addMappingsForFormatter(formatterBean, element.getId(), resolver, false);
                          }
  
                      }
                  }
                  if (getDetailContentId() != null) {
                      try {
                          CmsResource detailContent = m_cms.readResource(
                              getDetailContentId(),
                              CmsResourceFilter.ignoreExpirationOffline(m_cms));
                          CmsFormatterConfiguration config = OpenCms.getADEManager().lookupConfiguration(
                              m_cms,
                              m_cms.getRequestContext().getRootUri()).getFormatters(m_cms, detailContent);
                          for (I_CmsFormatterBean formatter : config.getDetailFormatters()) {
                              addMappingsForFormatter(formatter, getDetailContentId(), resolver, true);
                          }
                      } catch (CmsException e) {
                          LOG.error(
                              Messages.get().getBundle().key(
                                  Messages.ERR_READING_REQUIRED_RESOURCE_1,
                                  getDetailContentId()),
                              e);
                      }
                  }
              } catch (Exception e) {
                  LOG.error(e.getLocalizedMessage(), e);
              }
          }
      }