Common/Preparer/SalePreparer.php
protected function dispatchPrepareEvent(SaleInterface $sale)
    {
        if (!$sale instanceof OrderInterface) {
            throw new InvalidArgumentException("Expected instance of " . OrderInterface::class);
        }

        $event = $this->eventDispatcher->createResourceEvent($sale);

        try {
            $this->eventDispatcher->dispatch(OrderEvents::PREPARE, $event);
        } catch (IllegalOperationException $e) {
            return false;
        }

        return true;
    }
protected function dispatchPrepareEvent(SaleInterface $sale)
    {
        if (!$sale instanceof OrderInterface) {
            throw new InvalidArgumentException("Expected instance of " . OrderInterface::class);
        }

        $event = $this->eventDispatcher->createResourceEvent($sale);

        try {
            $this->eventDispatcher->dispatch(OrderEvents::PREPARE, $event);
        } catch (IllegalOperationException $e) {
            return false;
        }

        return true;
    }
Dispatches the sale prepare event.

@param SaleInterface $sale

@return bool