code: func (m *wsNotificationManager) RegisterTxOutAddressRequests(wsc *wsClient, addrs []string) {
  	m.queueNotification <- &notificationRegisterAddr{
  		wsc:   wsc,
  		addrs: addrs,
  	}
  }
docs: // RegisterTxOutAddressRequests requests notifications to the passed websocket
  // client when a transaction output spends to the passed address.