editingNodes.remove(node);
  public void addChildren(Experiment experiment) {    DefaultMutableTreeNode expNode = findNode(experiment);    // first remove old nodes    int n = expNode.getChildCount();    for (int i = 0; i < n; i++) {      DefaultMutableTreeNode node =         (DefaultMutableTreeNode)expNode.getChildAt(0);      model.removeNodeFromParent(node);      editingNodes.remove(node);    }    SocietyComponent society = experiment.getSocietyComponent();    if (society != null)      addSocietyToWorkspace(society, expNode);    RecipeComponent[] recipes = experiment.getRecipeComponents();    for (int i = 0; i < recipes.length; i++)      addRecipeToWorkspace(recipes[i], expNode);    workspace.setSelection(expNode);  }