private function parseConnectionString($connectionString)
    {
        $parts = explode(';', $connectionString);
        if (3 != count($parts)) {
            throw new \RuntimeException('Error parsing connection string: '.$connectionString);
        }

        foreach ($parts as $part) {
            if (0 === strpos($part, 'Endpoint')) {
                $this->endpoint = 'https'.substr($part, 11);
            } elseif (0 === strpos($part, 'SharedAccessKeyName')) {
                $this->sasKeyName = substr($part, 20);
            } elseif (0 === strpos($part, 'SharedAccessKey')) {
                $this->sasKeyValue = substr($part, 16);
            }
        }

        if (!$this->endpoint || !$this->sasKeyName || !$this->sasKeyValue) {
            throw new \RuntimeException('Invalid connection string: '.$connectionString);
        }
    }