/**
  * @param Order $order
  * @return Response
  */
 public function sendOrder(Order $order)
 {
     $url = sprintf("%s/venues/%s/stocks/%s/orders", $this->getUrl(), $order->getVenue(), $order->getSymbol());
     $response = new Response();
     try {
         $request = $this->client->post($url, ['json' => $order->toJson()]);
         $response->parseFromJson($request->getBody());
     } catch (RequestException $e) {
         // Do some magic Things...
     }
     return $response;
 }
<?php

if (!($loader = (include __DIR__ . '/../vendor/autoload.php'))) {
    die('You must set up the project dependencies.');
}
use Twinsen\StockFighterApi\Models\Order\Constants;
use Twinsen\StockFighterApi\Models\Order\Request\Order;
use Twinsen\StockFighterApi\Models\Manager\OrderManager;
use GuzzleHttp\Handler\MockHandler;
use GuzzleHttp\HandlerStack;
use GuzzleHttp\Psr7\Response;
$order = new Order();
$order->setSymbol('BAR');
$order->setVenue('FOOEX');
$order->setDirection(Constants::DIRECTION_BUY);
$order->setQty(20);
$order->setPrice(5100);
$order->setType(Constants::TYPE_LIMIT);
$order->setAccount('OGB12345');
$orderResponseJson = '
{
"ok": true,
"symbol": "BAR",
"venue": "FOOEX",
"direction": "buy",
"originalQty": 100,
"qty": 20,
"price":  5100,
"type": "limit",
"id": 12345,
"account" : "OGB12345",