Bridge/Symfony/Validator/SaleStepValidator.php
protected function getGroupsForStep($step)
    {
        $groups = ['Default'];

        if ($step === static::CHECKOUT_STEP) {
            $groups[] = 'Checkout';
            $groups[] = 'Identity';
            $groups[] = 'Availability';
        } elseif ($step === static::SHIPMENT_STEP) {
            $groups[] = 'Availability';
        }

        return $groups;
    }
protected function getGroupsForStep($step)
    {
        $groups = ['Default'];

        if ($step === static::CHECKOUT_STEP) {
            $groups[] = 'Checkout';
            $groups[] = 'Identity';
            $groups[] = 'Availability';
        } elseif ($step === static::SHIPMENT_STEP) {
            $groups[] = 'Availability';
        }

        return $groups;
    }
Returns the validation groups for the given step.

@param string $step

@return array