ShipmentCollection::isReserved

public function isReserved()
{
	if (!empty($this->collection) && is_array($this->collection))
	{
		/** @var Shipment $shipment */
		foreach ($this->collection as $shipment)
		{
			if ($shipment->isSystem())
			{
				if (count($this->collection) == 1)
					return $shipment->isReserved();

				continue;
			}

			if (!$shipment->isReserved())
				return false;
		}

		return true;
	}

	return false;
}