private static function getPageStreamingDescriptors()
{
$listTopicsPageStreamingDescriptor = new PageStreamingDescriptor(['requestPageTokenField' => 'page_token', 'requestPageSizeField' => 'page_size', 'responsePageTokenField' => 'next_page_token', 'resourceField' => 'topics']);
$listTopicSubscriptionsPageStreamingDescriptor = new PageStreamingDescriptor(['requestPageTokenField' => 'page_token', 'requestPageSizeField' => 'page_size', 'responsePageTokenField' => 'next_page_token', 'resourceField' => 'subscriptions']);
$pageStreamingDescriptors = ['listTopics' => $listTopicsPageStreamingDescriptor, 'listTopicSubscriptions' => $listTopicSubscriptionsPageStreamingDescriptor];
return $pageStreamingDescriptors;
}