Issue #3322646 by Sharique: Unknown function Unicode::strtolower and Unicode::strpos

namespace Drupal\webform_score\Plugin\WebformScore;

use Drupal\Component\Utility\Unicode;

use Drupal\Core\Form\FormStateInterface;

use Drupal\Core\TypedData\TypedDataInterface;

use Drupal\webform_score\Plugin\WebformScoreInterface;

    $answer = $answer->getValue();

    $expected = $this->configuration['expected'];

    if (!$this->configuration['case_sensitive']) {

      $answer = Unicode::strtolower($answer);

      $expected = Unicode::strtolower($expected);

      $answer = mb_strtolower($answer);

      $expected = mb_strtolower($expected);

    }

    return Unicode::strpos($answer, $expected) === FALSE ? 0 : $this->getMaxScore();

    return mb_strpos($answer, $expected) === FALSE ? 0 : $this->getMaxScore();

  }

  /**