translation_formatter.php

<?php

$formatter = function($entity) use ($preferredlanguage, $translatedFields) {
			foreach ($entity->translations as $translation) {
				if ($translation->locale === $preferredlanguage) {
					        $field = $translation->get('field');
					        $value = $translation->get('value');
						$entity->set($field, $value);
					}
				}
			}
		};