MemberManager::getCoveringKey

private function getCoveringKey(): ?string
{
	$coveringConfigs = $this->config->getCoveringConfigs();
	foreach ($coveringConfigs as $config)
	{
		if (isset(static::$cache[$this->getKey($config)]))
		{
			return $this->getKey($config);
		}
	}

	return null;
}