How to get old validation errors

Hello!

I know that is possible to use the function old() to get items from a redirect()->withInput().

My doubt is: How to get old validation errors? Has a function for that?

PHP Code:

public function withInput()
    {
        $session = $this->ensureSession();

        $input = [
            'get'  => $_GET ?? [],
            'post' => $_POST ?? [],
        ];

        $session->setFlashdata('_ci_old_input', $input);

        // If the validator has any errors, transmit those back
        // so they can be displayed when the validation is
        // handled within a method different than displaying the form.
        $validator = Services::validation();
        if (! empty($validator->getErrors()))
        {
            $session->setFlashdata('_ci_validation_errors', serialize($validator->getErrors()));
        }

        return $this;
    } 


Thank you very much!