pub fn scan<L, C, K>(
    wallet: Arc<Mutex<Box<dyn WalletInst<'static, L, C, K>>>>,
    keychain_mask: Option<&SecretKey>,
    args: CheckArgs
) -> Result<(), Error> where
    L: WalletLCProvider<'static, C, K> + 'static,
    C: NodeClient + 'static,
    K: Keychain + 'static,