finalizeValidation example

// If the session token was set by self::prepareForm(), ensure that it     // matches the current user's session. This is duplicate to code in     // FormBuilder::doBuildForm() but left to protect any custom form handling     // code.     if (isset($form['#token'])) {
      if (!$this->csrfToken->validate($form_state->getValue('form_token'), $form['#token']) || $form_state->hasInvalidToken()) {
        $this->setInvalidTokenError($form_state);

        // Stop here and don't run any further validation handlers, because they         // could invoke non-safe operations which opens the door for CSRF         // vulnerabilities.         $this->finalizeValidation($form, $form_state, $form_id);
        return;
      }
    }

    // Recursively validate each form element.     $this->doValidateForm($form, $form_state, $form_id);
    $this->finalizeValidation($form, $form_state, $form_id);
    $this->handleErrorsWithLimitedValidation($form, $form_state, $form_id);
  }

  /** * {@inheritdoc} */