public static function getMockZeroId(ClassMetadata $targetEntity)
    {
        if (!isset(self::$cacheZeroIds[$targetEntity->getName()])) {
            $type = self::getIdentifierType($targetEntity);
            self::$cacheZeroIds[$targetEntity->getName()] = self::findZeroIdValue($type);
        }

        return self::$cacheZeroIds[$targetEntity->getName()];
    }