14 files declare their use of YamlFormElementHelper in YAML Form 8

YamlForm.php in src/Entity/YamlForm.php

yamlform.theme.inc in includes/yamlform.theme.inc

Preprocessors and helper functions to make theming easier.

yamlform.translation.inc in includes/yamlform.translation.inc

YAML Form module translation hooks.

yamlform.update.inc in includes/yamlform.update.inc

YAML Form module update hooks.

YamlFormCompositeBase.php in src/Plugin/YamlFormElement/YamlFormCompositeBase.php

YamlFormElementBase.php in src/YamlFormElementBase.php

YamlFormElementHelperTest.php in tests/src/Unit/YamlFormElementHelperTest.php

YamlFormEntityElementsValidator.php in src/YamlFormEntityElementsValidator.php

YamlFormEntitySettingsForm.php in src/YamlFormEntitySettingsForm.php

YamlFormLikert.php in src/Plugin/YamlFormElement/YamlFormLikert.php

YamlFormMultiple.php in src/Element/YamlFormMultiple.php

YamlFormOptions.php in src/Element/YamlFormOptions.php

YamlFormSubmissionFormElementTest.php in src/Tests/YamlFormSubmissionFormElementTest.php

YamlFormTranslationManager.php in src/YamlFormTranslationManager.php