/// <summary> Constructor. </summary>
            /// <param name="tree"> The tree for which this node is valid. </param>
            /// <param name="registry"> The registry to store with this node. </param>
            private SignalNode(SignalRegistryTree tree, SignalListenerRegistry registry)
            {
                _tree   = tree;
                _lookup = new Dictionary <int, SignalNode>();

                Registry = registry;
            }
 /// <summary> Constructor. </summary>
 /// <param name="tree"> The tree for which this node is valid. </param>
 internal SignalNode(SignalRegistryTree tree)
     : this(tree, new SignalListenerRegistry())
 {
 }
 /// <summary> Constructor. </summary>
 /// <param name="tree"> The tree for which this signal broadcaster is valid. </param>
 public SignalBroadcaster(SignalRegistryTree tree)
 {
     _node    = tree.Root;
     _sources = new List <ISignalReceiver>();
 }