code: private void lockAllLocalizations(String key) throws CmsException {
  
          for (Locale l : m_bundleFiles.keySet()) {
              if ((null == l) || m_localizations.get(l).containsKey(key)) {
                  lockLocalization(l);
              }
          }
      }
docs: Locks all files of the currently edited bundle (that contain the provided key if it is not null).
  @param key the key that must be contained in the localization to lock. If null, the files for all localizations are locked.
  @throws CmsException thrown if locking fails.