public void AddConnection(long id, ConnectionReference connectionReference)
 {
     if (!_connectionReferences.TryAdd(id, connectionReference))
     {
         throw new ArgumentException("Unable to add connection.", nameof(id));
     }
 }
        public void AddConnection(long id, KestrelConnection connection)
        {
            var connectionReference = new ConnectionReference(id, connection, this);

            if (!_connectionReferences.TryAdd(id, connectionReference))
            {
                throw new ArgumentException("Unable to add specified id.", nameof(id));
            }

            _connectionManager.AddConnection(id, connectionReference);
        }