private boolean addAll(Collection<? extends ExternalSystemNode<?>> externalSystemNodes, boolean silently) {
    if (externalSystemNodes.isEmpty()) return false;

    if (myChildrenList == NO_CHILDREN_LIST) {
      myChildrenList = new CopyOnWriteArrayList<>();
    }

    for (ExternalSystemNode<?> externalSystemNode : externalSystemNodes) {
      externalSystemNode.setParent(this);
      myChildrenList.add(externalSystemNode);
    }
    if (!silently) {
      childrenChanged();
    }

    return true;
  }
private boolean addAll(Collection<? extends ExternalSystemNode<?>> externalSystemNodes, boolean silently)