public void registerWalletBusyListener(WalletBusyListener walletBusyListener){
  walletBusyListeners.add(walletBusyListener);
}

public void registerWalletBusyListener ( WalletBusyListener walletBusyListener ) { walletBusyListeners . add ( walletBusyListener ) ; }
register a new walletbusylistener .
