class PhpTransliteration

class PhpTransliteration extends BaseTransliteration {
    
    /**
     * The module handler to execute the transliteration_overrides alter hook.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * Constructs a PhpTransliteration object.
     *
     * @param string $data_directory
     *   The directory where data files reside. If NULL, defaults to subdirectory
     *   'data' underneath the directory where the class's PHP file resides.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler to execute the transliteration_overrides alter hook.
     */
    public function __construct($data_directory, ModuleHandlerInterface $module_handler) {
        parent::__construct($data_directory);
        $this->moduleHandler = $module_handler;
    }
    
    /**
     * Overrides \Drupal\Component\Transliteration\PhpTransliteration::readLanguageOverrides().
     *
     * Allows modules to alter the language-specific $overrides array by invoking
     * hook_transliteration_overrides_alter().
     */
    protected function readLanguageOverrides($langcode) {
        parent::readLanguageOverrides($langcode);
        // Let modules alter the language-specific overrides.
        $this->moduleHandler
            ->alter('transliteration_overrides', $this->languageOverrides[$langcode], $langcode);
    }

}