public void insert(final User user) {
        chains().of(stream -> stream.forEach(c -> c.update(user)));
    }

    public boolean changePassword(final String username, final String password) {
        return chains().get(stream -> stream.allMatch(c -> c.changePassword(username, password)));
    }

    public void delete(final User user) {
        chains().of(stream -> stream.forEach(c -> c.delete(user)));
    }