boolean (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; }