在Constant Contact中查看电子邮件地址

Question

我无法找到使用Constant Contact REST API检查电子邮件地址是否在列表中的文档。

以下似乎完全没用：

include_once('cc_class.php');
$ccContactOBJ = new CC_Contact("basic", $cckey, $ccuser, $ccpass);
if(($_SERVER['REQUEST_METHOD']=="POST") && !empty($_REQUEST['member-submit'])) {
$contact = $ccContactOBJ->getSubscribers(urlencode($_POST['MemberEmail']));

if (empty($contact['items'])) {
    $message = 'You are not listed in our database.';      
}
else {
    $message = 'You are already listed in our database';     
}
echo $message; 

}

任何人都知道如何返回真值或假值？