t() calls should be avoided in classes

$ phpcs --standard=Drupalpractice --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml optional_date/

FILE: C:\xampp\htdocs\contribution\web\modules\contrib\optional_date\src\Plugin\Field\FieldType\OptionalDateItem.php
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FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
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90 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
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FILE: C:\xampp\htdocs\contribution\web\modules\contrib\optional_date\src\Plugin\Field\FieldType\OptionalDateRangeItem.php
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FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
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112 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
118 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
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Time: 1.56 secs; Memory: 6MB