protected function getCachedRelationCount($propertyName)
    {
        if (array_key_exists($propertyName, $this->cachedRelationCountsCount)) {
            return $this->cachedRelationCountsCount[$propertyName];
        }

        $this->cachedRelationCountsCount[$propertyName] = $this->getUncachedRelationCount($propertyName);

        return $this->cachedRelationCountsCount[$propertyName];
    }