void ProcessNodesAddRemove(Set<Node> requiredNodes, Set<Node> existindNodes) {
lock (this) {
foreach (var node in existindNodes.Where(node => !requiredNodes.Contains(node)))
HideVNode(node);
foreach (var node in requiredNodes.Where(node => !existindNodes.Contains(node)))
UnhideVNode(node);
}
}
