我有一个简单的代码。如何为它编写测试?

当我编写这段代码时,我没有使用phpunit和函数测试,因为我不知道如何为这段代码编写测试。我知道如何为其他函数和代码编写测试,但我不知道这段代码需要哪个测试。有人能解释吗? 所有功能都是Google AdWords API。不是我自己的。我也不需要测试它们。

    $adStatsSelector = new AdStatsSelector();
$adStatsSelector->dateRange = new
      DateRange('20100901','20101001');
$user = new AdWordsUser();
$user->LogDefaults();
$servicedAccountService = $user->GetServicedAccountService('v201008');
$selector = new ServicedAccountSelector(); 
$graph = $servicedAccountService->get($selector); 
foreach($graph->accounts as &$account) {
    $user->SetClientId($account->login);
    $campaignService = $user->GetCampaignService('v201008');
    $selector = new CampaignSelector(null,null,$adStatsSelector);
    $page = $campaignService->get($selector);
    $account->campaigns = $page->entries;
}