protected function loadFulfillmentMethods()
    {
        $this->fulfillmentMethodsByType = new ArrayCollection();
        foreach ($this->configuration as $type => $configurationFulfillmentMethods) {
            foreach ($configurationFulfillmentMethods  as $configurationFulfillmentMethod) {

                if (array_key_exists('class', $configurationFulfillmentMethod)) {

                    $class = $configurationFulfillmentMethod['class'];
                    $fulfillmentMethod = new $class();

                    $fulfillmentMethodsInType = $this->fulfillmentMethodsByType->get($type);

                    if (!$fulfillmentMethodsInType) {
                        $fulfillmentMethodsInType = new ArrayCollection();
                        $this->fulfillmentMethodsByType->set($type, $fulfillmentMethodsInType);
                    }
                    $fulfillmentMethodsInType->add($fulfillmentMethod);
               }
            }
        }
    }