materio-d8/web/modules/custom/materio_sapi/src/CountryNameComputed.php

<?php

namespace Drupal\materio_sapi;

use Drupal\Core\Field\FieldItemList;
use Drupal\Core\TypedData\ComputedItemListTrait;

class CountryNameComputed extends FieldItemList {
  use ComputedItemListTrait;

  protected function computeValue() {
    $term = $this->getEntity();
    $name = $term->getName();
    $address = $term->get('field_public_address')->first();
    if ($address) {
      $country_code = $address->getCountryCode();
      if ($country_code) {
        $full_country_list = \Drupal::service('country_manager')->getList();
        $country_name = $full_country_list[$country_code];
        $lang = \Drupal::languageManager()->getCurrentLanguage()->getId();
        $translated_markup = $country_name->render();
        if($parent->id() == 5719){
          $t="t";
        }
        $this->list[0] = $this->createItem(0, $translated_markup);
      }
    }
  }
}