class AbstractMeta implements ChangedFlagInterface, UndoInterface, HasDatabasesInterface, VariableSpace,
  EngineMetaInterface, NamedParams, HasSlaveServersInterface, AttributesInterface, HasRepositoryInterface,
  LoggingObjectInterface {

  public void addFilenameChangedListener( FilenameChangedListener listener ) {
    if ( filenameChangedListeners == null ) {
      filenameChangedListeners = new ArrayList<FilenameChangedListener>();
    }
    if ( listener != null ) {
      filenameChangedListeners.add( listener );
    }
  }

}