public Authentication getAuthentication() {
        return new AuthenticationImpl(getAuthScope(), getCredentials(), getAuthScheme());
    }

    private AuthScheme getAuthScheme() {
        final String scheme = getProtocolScheme();
        if (Constants.BASIC.equals(scheme)) {
            return new BasicScheme();
        }
        if (Constants.DIGEST.equals(scheme)) {
            return new DigestScheme();
        }