t() calls should be avoided in classes

FILE: ...ontrib/cancel_button/tests/src/Functional/CancelButtonSettingsFormTest.php
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FOUND 0 ERRORS AND 3 WARNINGS AFFECTING 3 LINES
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67 | WARNING | t() calls should be avoided in classes, use
| | \Drupal\Core\StringTranslation\StringTranslationTrait and
| | $this->t() instead
114 | WARNING | t() calls should be avoided in classes, use
| | \Drupal\Core\StringTranslation\StringTranslationTrait and
| | $this->t() instead
115 | WARNING | t() calls should be avoided in classes, use
| | \Drupal\Core\StringTranslation\StringTranslationTrait and
| | $this->t() instead