public void login(final List<String> servers) {
        if ((System.currentTimeMillis() - lastRefreshTime) < (tokenExpiredTime - tokenRefreshWindow)) {
            return;
        }
        for (String server : servers) {
            if (this.doLogin(server)) {
                this.lastRefreshTime = System.currentTimeMillis();
                return;
            }
        }
    }
@Test
    public void testLogin() {
        accessTokenManager.login(Lists.newArrayList(httpConfig.getUrl().split(",")));
        assertEquals(this.accessToken, accessTokenManager.getAccessToken());
    }