private Collection getLayersWithModifiedFeatureCollections() {
    ArrayList layersWithModifiedFeatureCollections = new ArrayList();
    for (Iterator i = getLayerManagers().iterator(); i.hasNext(); ) {
      LayerManager layerManager = (LayerManager) i.next();
      layersWithModifiedFeatureCollections.addAll(
          layerManager.getLayersWithModifiedFeatureCollections());
    }

    return layersWithModifiedFeatureCollections;
  }