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

    for (ExternalSystemNode<?> externalSystemNode : externalSystemNodes) {
      externalSystemNode.setParent(null);
      if (myChildrenList != NO_CHILDREN_LIST) myChildrenList.remove(externalSystemNode);
    }
    if (!silently) {
      childrenChanged();
    }

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