public void ErrorOccurred(INode node, Exception exc = null)
 {
     lock (_lock)
     {
         Blacklisted.AddNode(node);
         RefreshServerQueue();
         exc.InitializeIfNull(new Exception("Unknown exception"));
         ErrorCallback.NotNull(a => a(new HeliosNodeException(exc, node)));
     }
 }
 public void ErrorOccurred(INode node, Exception exc = null)
 {
     exc.InitializeIfNull(new Exception("Unknown exception"));
     ErrorCallback.NotNull(a => a(new HeliosNodeException(exc, node)));
 }