protected function validateSize($size)
    {
        if (! is_int($size) && ! ctype_digit($size)) {
            throw new \InvalidArgumentException('Avatar size specified must be an integer');
        }

        if ($size < 0 || $size > 2048) {
            throw new \InvalidArgumentException('Avatar size must be within 0 pixels and 2048 pixels');
        }
    }