code: private void lockOnChange(Object propertyId) throws CmsException {
  
          if (isDescriptorProperty(propertyId)) {
              lockDescriptor();
          } else {
              Locale l = m_bundleType.equals(BundleType.PROPERTY) ? m_locale : null;
              lockLocalization(l);
          }
  
      }
docs: Lock a file lazily, if a value that should be written to the file has changed.
  @param propertyId the table column in which the value has changed (e.g., KEY, TRANSLATION, ...)
  @throws CmsException thrown if locking fails.