Predis\Connection\StreamConnection::tcpStreamInitializer PHP Method

    protected function tcpStreamInitializer(ParametersInterface $parameters)
    {
        if (!filter_var($parameters->host, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
            $address = "tcp://{$parameters->host}:{$parameters->port}";
        } else {
            $address = "tcp://[{$parameters->host}]:{$parameters->port}";
        }
        $flags = STREAM_CLIENT_CONNECT;
        if (isset($parameters->async_connect) && $parameters->async_connect) {
            $flags |= STREAM_CLIENT_ASYNC_CONNECT;
        }
        if (isset($parameters->persistent)) {
            if (false !== ($persistent = filter_var($parameters->persistent, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE))) {
                $flags |= STREAM_CLIENT_PERSISTENT;
                if ($persistent === null) {
                    $address = "{$address}/{$parameters->persistent}";
                }
            }
        }
        $resource = $this->createStreamSocket($parameters, $address, $flags);
        return $resource;
    }