public void removeDiagramChangeListener(mxDiagramChangeListener listener){
  if (diagramChangeListeners != null) {
    diagramChangeListeners.remove(listener);
  }
}

public void removeDiagramChangeListener ( mxDiagramChangeListener listener ) { if ( diagramChangeListeners != null ) { diagramChangeListeners . remove ( listener ) ; } }
removes the given listener from the list of diagram change listeners .
