public function avatar(string $email, array $options = [], ?bool $secure = null, bool $validateOptions = false): string
    {
        $url = 'avatar/'.$this->createEmailHash($email);

        $options = array_merge($this->defaults, array_filter($options));

        if ($validateOptions) {
            $this->validateOptions($options);
        }

        if (!empty($options)) {
            $url .= '?'.http_build_query($options);
        }

        return $this->buildUrl($url, $secure);
    }