public IGroup GetReference(IActivatable lightProvider)
 {
     lock (_lock)
     {
         GroupReference gRef = new GroupReference(Name, Lights, lightProvider);
         _referring.Add(new WeakReference<GroupReference>(gRef));
         return gRef;
     }
 }
 internal MasterGroup(string name, IEnumerable<LightAddress> addresses, IActivatable lightProvider)
 {
     _me = new GroupReference(name, addresses, lightProvider);
 }