private synchronized void addActions(@NotNull List<? extends AnAction> actions) {
    Set<AnAction> actionSet = new HashSet<>(actions.size());
    List<AnAction> uniqueActions = new ArrayList<>(actions.size());
    for (AnAction action : actions) {
      if (action == this) {
        LOG.error(newThisGroupToItselfAddedException());
      }
      else if (action == null) {
        LOG.error(nullActionAddedToTheGroupException());
      }
      else if (!(action instanceof Separator || actionSet.add(action))) {
        LOG.error(newDuplicateActionAddedException(action));
      }
      else {
        uniqueActions.add(action);
      }
    }
    mySortedChildren.addAll(uniqueActions);
    incrementModificationStamp();
  }
private synchronized void addActions(@NotNull List<? extends AnAction> actions)