class Wallet {

    public boolean unlockAccount(UscAddress addr, String passphrase, long duration) {
        long ending = System.currentTimeMillis() + duration;
        boolean unlocked = unlockAccount(addr, passphrase);

        if (unlocked) {
            synchronized (accessLock) {
                unlocksTimeouts.put(addr, ending);
            }
        }

        return unlocked;
    }

    public  Wallet(KeyValueDataSource keyDS);

}