MongoClient::connectToFirstAvailableHost PHP Method

    private function connectToFirstAvailableHost()
    {
        if (count($this->protocols) > 0) {
            return reset($this->protocols);
        }
        $latest_error = null;
        foreach ($this->hosts as $host_key => &$host_info) {
            try {
                $protocol = $this->connectToHost($host_info['host'], $host_info['port']);
                // We were able to connect, so update host status
                $host_info['health'] = static::HEALTHY;
                // assume healthy since we connected
                $host_info['state'] = static::STATE_STARTUP;
                // Default to unknown
                return $protocol;
            } catch (MongoConnectionException $e) {
                $latest_error = $e;
                continue;
            }
        }
        $msg = "Could not connect to any of " . count($this->hosts) . " hosts. Latest error: " . ($latest_error ? $latest_error->getMessage() : '');
        throw new MongoConnectionException($msg);
    }