Sylius\Behat\Page\Shop\Checkout\SelectShippingPageInterface::getValidationMessageForShipment PHP Method

    public function getValidationMessageForShipment();

 /**
  * @Then I should be notified that the shipping method is required
  */
 public function iShouldBeNotifiedThatTheShippingMethodIsRequired()
 {
     Assert::same($this->selectShippingPage->getValidationMessageForShipment(), 'Please select shipping method.');
 }