Unreachable variable while working with Google AdWords API in PHP - php

Question

I have a problem in PHP and I can't seem to solve it. I am using Google AdWords API to create campaigns. So first of all I create a new Campaign, and after that new GroupAd. Problem is that I get campaign ID when creating campaign, and although I save that ID in variable $mycampaignID, I can't use it in another class where I am creating GroupAd. Can someone help me with this? I tried using global variable, public variable, etc., but none of it seems to work properly. Here is just a part of the code, you can see how classes and function look like.
class AddCampaigns
{
public static function runExample(
AdWordsServices $adWordsServices,
AdWordsSession $session
) {
$result = $campaignService->mutate($operations);
foreach ($result->getValue() as $campaign) {
**$mycampaignID** = $campaign->getId();
printf(
"Campaign with name '%s' and ID %d was added.\n",
$campaign->getName(),
$campaign->getId()
);
}
}
}
AddCampaigns::main();
class AddAdGroups
{
const CAMPAIGN_ID = **$mycampaignID**;
public static function runExample(
AdWordsServices $adWordsServices,
AdWordsSession $session,
$campaignId
) {
$adGroupService = $adWordsServices->get($session, AdGroupService::class);
}
}
AddAdGroups::main();