public function importSubscribers($subscribers, $listId = null)
{
// set parameters
$parameters['Subscribers'] = $subscribers;
$parameters['Resubscribe'] = 'true';
// make the call
$results = $this->doCall('subscribers/' . $listId . '/import', $parameters, 'POST');
// check if we have failed results in the result set
if (empty($results['ResultData']['FailureDetails'])) {
return array();
}
// reserve failed stack
$failed = array();
// loop the failed results
foreach ($results['ResultData']['FailureDetails'] as $result) {
$failed[] = $result['EmailAddress'];
}
// return the failed results
return $failed;
}