code: protected void initLocalizationContent(String configurationFileName) {
  
          CmsObject cms = null;
          try {
              // this will always be in the root site
              cms = OpenCms.initCmsObject(OpenCms.getDefaultUsers().getUserGuest());
          } catch (CmsException e) {
              // error initializing cms object, log error
              if (LOG.isErrorEnabled()) {
                  LOG.error(
                      Messages.get().getBundle().key(
                          Messages.ERR_INVALID_INIT_USER_1,
                          OpenCms.getDefaultUsers().getUserGuest()));
              }
          }
          if ((cms != null) && CmsStringUtil.isNotEmptyOrWhitespaceOnly(configurationFileName)) {
              // try to get XML content from cache
              Object o = CmsVfsMemoryObjectCache.getVfsMemoryObjectCache().getCachedObject(cms, configurationFileName);
              if (o != null) {
                  // found the cached XML content, use it
                  m_localizationContent = (CmsXmlContent)o;
                  return;
              }
              try {
                  CmsFile configFile = cms.readFile(configurationFileName);
                  m_localizationContent = CmsXmlContentFactory.unmarshal(cms, configFile);
                  // store unmarshaled content in cache
                  CmsVfsMemoryObjectCache.getVfsMemoryObjectCache().putCachedObject(
                      cms,
                      configurationFileName,
                      m_localizationContent);
              } catch (CmsException e) {
                  // ignore, no configuration file found
              }
          }
      }
docs: Initializes the content used for localizing the output.<p>
  
  @param configurationFileName the absolute path including site root to the configuration file containing localized keys