src/Form/SummaryForm.php
public function isValid()
    {
        $isValid = parent::isValid();
        if ($isValid) {
            $this->setRenderMode(self::RENDER_SUMMARY);
        }
        
        return $isValid;
    }
public function isValid()
    {
        $isValid = parent::isValid();
        if ($isValid) {
            $this->setRenderMode(self::RENDER_SUMMARY);
        }
        
        return $isValid;
    }
{@inheritDoc}

Sets render mode to {@link RENDER_SUMMARY}, if validation succeeded.

@see \Zend\Form\Form::isValid()