public function getRawContent()
    {
        if ($this->size == 0) {
            return '';
        }

        if ($this->encoding === 'base64') {
            $raw = base64_decode($this->content, true);
            if ($raw === false) {
                throw new \RuntimeException('Failed to decode content');
            }

            return $raw;
        }

        throw new \RuntimeException('Unrecognised blob encoding: ' . $this->encoding);
    }