@Override
    public void login(final LoginCallback prompt, final CancelCallback cancel) throws BackgroundException {
        authorizationService.validate();
    }
@Test(expected = LoginCanceledException.class)
    public void testConnectMissingKey() throws Exception {
        session.close();
        session.getHost().getCredentials().setOauth(OAuthTokens.EMPTY);
        session.login(new DisabledLoginCallback() {
            @Override
            public Credentials prompt(final Host bookmark, final String username,
                                      final String title, final String reason, final LoginOptions options) throws LoginCanceledException {
                assertEquals("OAuth2 Authentication", title);
                throw new LoginCanceledException();
            }
        }, null);
    }